Table of prime factors
The tables contain the prime factorization of the natural numbers from 1 to 1000.
When n is a prime number, the prime factorization is just n itself, written in bold below.
The number 1 is called a unit. It has no prime factors and is neither prime nor composite.
See also: Table of divisors (prime and non-prime divisors for 1 to 1000)
Properties
Many properties of a natural number n can be seen or directly computed from the prime factorization of n.
- The multiplicity of a prime factor p of n is the largest exponent m for which pm divides n. The tables show the multiplicity for each prime factor. If no exponent is written then the multiplicity is 1 (since p = p1). The multiplicity of a prime which does not divide n may be called 0 or may be considered undefined.
- Ω(n), the big Omega function, is the number of prime factors of n counted with multiplicity (so it is the sum of all prime factor multiplicities).
- A prime number has Ω(n) = 1. The first: 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37 (sequence A000040 in the OEIS). There are many special types of prime numbers.
- A composite number has Ω(n) > 1. The first: 4, 6, 8, 9, 10, 12, 14, 15, 16, 18, 20, 21 (sequence A002808 in the OEIS). All numbers above 1 are either prime or composite. 1 is neither.
- A semiprime has Ω(n) = 2 (so it is composite). The first: 4, 6, 9, 10, 14, 15, 21, 22, 25, 26, 33, 34 (sequence A001358 in the OEIS).
- A k-almost prime (for a natural number k) has Ω(n) = k (so it is composite if k > 1).
- An even number has the prime factor 2. The first: 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24 (sequence A005843 in the OEIS).
- An odd number does not have the prime factor 2. The first: 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23 (sequence A005408 in the OEIS). All integers are either even or odd.
- A square has even multiplicity for all prime factors (it is of the form a2 for some a). The first: 1, 4, 9, 16, 25, 36, 49, 64, 81, 100, 121, 144 (sequence A000290 in the OEIS).
- A cube has all multiplicities divisible by 3 (it is of the form a3 for some a). The first: 1, 8, 27, 64, 125, 216, 343, 512, 729, 1000, 1331, 1728 (sequence A000578 in the OEIS).
- A perfect power has a common divisor m > 1 for all multiplicities (it is of the form am for some a > 1 and m > 1). The first: 4, 8, 9, 16, 25, 27, 32, 36, 49, 64, 81, 100 (sequence A001597 in the OEIS). 1 is sometimes included.
- A powerful number (also called squareful) has multiplicity above 1 for all prime factors. The first: 1, 4, 8, 9, 16, 25, 27, 32, 36, 49, 64, 72 (sequence A001694 in the OEIS).
- A prime power has only one prime factor. The first: 2, 3, 4, 5, 7, 8, 9, 11, 13, 16, 17, 19 (sequence A000961 in the OEIS). 1 is sometimes included.
- An Achilles number is powerful but not a perfect power. The first: 72, 108, 200, 288, 392, 432, 500, 648, 675, 800, 864, 968 (sequence A052486 in the OEIS).
- A square-free integer has no prime factor with multiplicity above 1. The first: 1, 2, 3, 5, 6, 7, 10, 11, 13, 14, 15, 17 (sequence A005117 in the OEIS)). A number where some but not all prime factors have multiplicity above 1 is neither square-free nor squareful.
- The Liouville function λ(n) is 1 if Ω(n) is even, and is -1 if Ω(n) is odd.
- The Möbius function μ(n) is 0 if n is not square-free. Otherwise μ(n) is 1 if Ω(n) is even, and is −1 if Ω(n) is odd.
- A sphenic number has Ω(n) = 3 and is square-free (so it is the product of 3 distinct primes). The first: 30, 42, 66, 70, 78, 102, 105, 110, 114, 130, 138, 154 (sequence A007304 in the OEIS).
- a0(n) is the sum of primes dividing n, counted with multiplicity. It is an additive function.
- A Ruth-Aaron pair is two consecutive numbers (x, x+1) with a0(x) = a0(x+1). The first (by x value): 5, 8, 15, 77, 125, 714, 948, 1330, 1520, 1862, 2491, 3248 (sequence A039752 in the OEIS), another definition is the same prime only count once, if so, the first (by x value): 5, 24, 49, 77, 104, 153, 369, 492, 714, 1682, 2107, 2299 (sequence A006145 in the OEIS)
- A primorial x# is the product of all primes from 2 to x. The first: 2, 6, 30, 210, 2310, 30030, 510510, 9699690, 223092870, 6469693230, 200560490130, 7420738134810 (sequence A002110 in the OEIS). 1# = 1 is sometimes included.
- A factorial x! is the product of all numbers from 1 to x. The first: 1, 2, 6, 24, 120, 720, 5040, 40320, 362880, 3628800, 39916800, 479001600 (sequence A000142 in the OEIS). 0! = 1 is sometimes included.
- A k-smooth number (for a natural number k) has largest prime factor ≤ k (so it is also j-smooth for any j > k).
- m is smoother than n if the largest prime factor of m is below the largest of n.
- A regular number has no prime factor above 5 (so it is 5-smooth). The first: 1, 2, 3, 4, 5, 6, 8, 9, 10, 12, 15, 16 (sequence A051037 in the OEIS).
- A k-powersmooth number has all pm ≤ k where p is a prime factor with multiplicity m.
- A frugal number has more digits than the number of digits in its prime factorization (when written like below tables with multiplicities above 1 as exponents). The first in decimal: 125, 128, 243, 256, 343, 512, 625, 729, 1024, 1029, 1215, 1250 (sequence A046759 in the OEIS).
- An equidigital number has the same number of digits as its prime factorization. The first in decimal: 1, 2, 3, 5, 7, 10, 11, 13, 14, 15, 16, 17 (sequence A046758 in the OEIS).
- An extravagant number has fewer digits than its prime factorization. The first in decimal: 4, 6, 8, 9, 12, 18, 20, 22, 24, 26, 28, 30 (sequence A046760 in the OEIS).
- An economical number has been defined as a frugal number, but also as a number that is either frugal or equidigital.
- gcd(m, n) (greatest common divisor of m and n) is the product of all prime factors which are both in m and n (with the smallest multiplicity for m and n).
- m and n are coprime (also called relatively prime) if gcd(m, n) = 1 (meaning they have no common prime factor).
- lcm(m, n) (least common multiple of m and n) is the product of all prime factors of m or n (with the largest multiplicity for m or n).
- gcd(m, n) × lcm(m, n) = m × n. Finding the prime factors is often harder than to compute gcd and lcm with other algorithms which do not require known prime factorization.
- m is a divisor of n (also called m divides n, or n is divisible by m) if all prime factors of m have at least the same multiplicity in n.
The divisors of n are all products of some or all prime factors of n (including the empty product 1 of no prime factors).
The number of divisors can be computed by increasing all multiplicities by 1 and then multiplying them.
Divisors and properties related to divisors are shown in table of divisors.
1 to 100
101 to 200
201 to 300
301 to 400
401 to 500
501 to 600
601 to 700
701 to 800
801 to 900
801 - 820
801 | 32·89 |
802 | 2·401 |
803 | 11·73 |
804 | 22·3·67 |
805 | 5·7·23 |
806 | 2·13·31 |
807 | 3·269 |
808 | 23·101 |
809 | 809 |
810 | 2·34·5 |
811 | 811 |
812 | 22·7·29 |
813 | 3·271 |
814 | 2·11·37 |
815 | 5·163 |
816 | 24·3·17 |
817 | 19·43 |
818 | 2·409 |
819 | 32·7·13 |
820 | 22·5·41 |
|
821 - 840
821 | 821 |
822 | 2·3·137 |
823 | 823 |
824 | 23·103 |
825 | 3·52·11 |
826 | 2·7·59 |
827 | 827 |
828 | 22·32·23 |
829 | 829 |
830 | 2·5·83 |
831 | 3·277 |
832 | 26·13 |
833 | 72·17 |
834 | 2·3·139 |
835 | 5·167 |
836 | 22·11·19 |
837 | 33·31 |
838 | 2·419 |
839 | 839 |
840 | 23·3·5·7 |
|
841 - 860
841 | 292 |
842 | 2·421 |
843 | 3·281 |
844 | 22·211 |
845 | 5·132 |
846 | 2·32·47 |
847 | 7·112 |
848 | 24·53 |
849 | 3·283 |
850 | 2·52·17 |
851 | 23·37 |
852 | 22·3·71 |
853 | 853 |
854 | 2·7·61 |
855 | 32·5·19 |
856 | 23·107 |
857 | 857 |
858 | 2·3·11·13 |
859 | 859 |
860 | 22·5·43 |
|
861 - 880
861 | 3·7·41 |
862 | 2·431 |
863 | 863 |
864 | 25·33 |
865 | 5·173 |
866 | 2·433 |
867 | 3·172 |
868 | 22·7·31 |
869 | 11·79 |
870 | 2·3·5·29 |
871 | 13·67 |
872 | 23·109 |
873 | 32·97 |
874 | 2·19·23 |
875 | 53·7 |
876 | 22·3·73 |
877 | 877 |
878 | 2·439 |
879 | 3·293 |
880 | 24·5·11 |
|
881 - 900
881 | 881 |
882 | 2·32·72 |
883 | 883 |
884 | 22·13·17 |
885 | 3·5·59 |
886 | 2·443 |
887 | 887 |
888 | 23·3·37 |
889 | 7·127 |
890 | 2·5·89 |
891 | 34·11 |
892 | 22·223 |
893 | 19·47 |
894 | 2·3·149 |
895 | 5·179 |
896 | 27·7 |
897 | 3·13·23 |
898 | 2·449 |
899 | 29·31 |
900 | 22·32·52 |
|
901 to 1000
901 - 920
901 | 17·53 |
902 | 2·11·41 |
903 | 3·7·43 |
904 | 23·113 |
905 | 5·181 |
906 | 2·3·151 |
907 | 907 |
908 | 22·227 |
909 | 32·101 |
910 | 2·5·7·13 |
911 | 911 |
912 | 24·3·19 |
913 | 11·83 |
914 | 2·457 |
915 | 3·5·61 |
916 | 22·229 |
917 | 7·131 |
918 | 2·33·17 |
919 | 919 |
920 | 23·5·23 |
|
921 - 940
921 | 3·307 |
922 | 2·461 |
923 | 13·71 |
924 | 22·3·7·11 |
925 | 52·37 |
926 | 2·463 |
927 | 32·103 |
928 | 25·29 |
929 | 929 |
930 | 2·3·5·31 |
931 | 72·19 |
932 | 22·233 |
933 | 3·311 |
934 | 2·467 |
935 | 5·11·17 |
936 | 23·32·13 |
937 | 937 |
938 | 2·7·67 |
939 | 3·313 |
940 | 22·5·47 |
|
941 - 960
941 | 941 |
942 | 2·3·157 |
943 | 23·41 |
944 | 24·59 |
945 | 33·5·7 |
946 | 2·11·43 |
947 | 947 |
948 | 22·3·79 |
949 | 13·73 |
950 | 2·52·19 |
951 | 3·317 |
952 | 23·7·17 |
953 | 953 |
954 | 2·32·53 |
955 | 5·191 |
956 | 22·239 |
957 | 3·11·29 |
958 | 2·479 |
959 | 7·137 |
960 | 26·3·5 |
|
961 - 980
961 | 312 |
962 | 2·13·37 |
963 | 32·107 |
964 | 22·241 |
965 | 5·193 |
966 | 2·3·7·23 |
967 | 967 |
968 | 23·112 |
969 | 3·17·19 |
970 | 2·5·97 |
971 | 971 |
972 | 22·35 |
973 | 7·139 |
974 | 2·487 |
975 | 3·52·13 |
976 | 24·61 |
977 | 977 |
978 | 2·3·163 |
979 | 11·89 |
980 | 22·5·72 |
|
981 - 1000
981 | 32·109 |
982 | 2·491 |
983 | 983 |
984 | 23·3·41 |
985 | 5·197 |
986 | 2·17·29 |
987 | 3·7·47 |
988 | 22·13·19 |
989 | 23·43 |
990 | 2·32·5·11 |
991 | 991 |
992 | 25·31 |
993 | 3·331 |
994 | 2·7·71 |
995 | 5·199 |
996 | 22·3·83 |
997 | 997 |
998 | 2·499 |
999 | 33·37 |
1000 | 23·53 |
|
See also