257101561 has 2 divisors, whose sum is σ = 257101562. Its totient is φ = 257101560.

The previous prime is 257101541. The next prime is 257101571. The reversal of 257101561 is 165101752.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 170145936 + 86955625 = 13044^2 + 9325^2 .

It is a cyclic number.

It is not a de Polignac number, because 257101561 - 2²⁷ = 122883833 is a prime.

It is a super-2 number, since 2×257101561² = 132202425337273442, which contains 22 as substring.

It is a Chen prime.

It is equal to p_14046256 and since 257101561 and 14046256 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (257101541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128550780 + 128550781.

It is an arithmetic number, because the mean of its divisors is an integer number (128550781).

Almost surely, 2^257101561 is an apocalyptic number.

It is an amenable number.

257101561 is a deficient number, since it is larger than the sum of its proper divisors (1).

257101561 is an equidigital number, since it uses as much as digits as its factorization.

257101561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2100, while the sum is 28.

The square root of 257101561 is about 16034.3868295610. The cubic root of 257101561 is about 635.8698567154.

The spelling of 257101561 in words is "two hundred fifty-seven million, one hundred one thousand, five hundred sixty-one".