Base | Representation |
---|---|
bin | 11110100101000… |
… | …11011100000101 |
3 | 122212200200000102 |
4 | 33102203130011 |
5 | 1011132200424 |
6 | 41242053445 |
7 | 6233254343 |
oct | 1722433405 |
9 | 585620012 |
10 | 256521989 |
11 | 121888849 |
12 | 71aaa285 |
13 | 411b7179 |
14 | 260d6993 |
15 | 177c17ae |
hex | f4a3705 |
256521989 has 2 divisors, whose sum is σ = 256521990. Its totient is φ = 256521988.
The previous prime is 256521949. The next prime is 256521997. The reversal of 256521989 is 989125652.
256521989 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.
It is a strong prime.
It can be written as a sum of positive squares in only one way, i.e., 255040900 + 1481089 = 15970^2 + 1217^2 .
It is a cyclic number.
It is a de Polignac number, because none of the positive numbers 2k-256521989 is a prime.
It is a super-2 number, since 2×2565219892 = 131607061681032242, which contains 22 as substring.
It is a Chen prime.
It is a congruent number.
It is not a weakly prime, because it can be changed into another prime (256521919) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128260994 + 128260995.
It is an arithmetic number, because the mean of its divisors is an integer number (128260995).
Almost surely, 2256521989 is an apocalyptic number.
It is an amenable number.
256521989 is a deficient number, since it is larger than the sum of its proper divisors (1).
256521989 is an equidigital number, since it uses as much as digits as its factorization.
256521989 is an evil number, because the sum of its binary digits is even.
The product of its digits is 388800, while the sum is 47.
The square root of 256521989 is about 16016.3038495153. The cubic root of 256521989 is about 635.3916933621.
The spelling of 256521989 in words is "two hundred fifty-six million, five hundred twenty-one thousand, nine hundred eighty-nine".
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