257605531 has 2 divisors, whose sum is σ = 257605532. Its totient is φ = 257605530.

The previous prime is 257605529. The next prime is 257605541. The reversal of 257605531 is 135506752.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 257605531 - 2¹ = 257605529 is a prime.

It is a super-2 number, since 2×257605531² = 132721219203583922, which contains 22 as substring.

Together with 257605529, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (257605511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128802765 + 128802766.

It is an arithmetic number, because the mean of its divisors is an integer number (128802766).

Almost surely, 2^257605531 is an apocalyptic number.

257605531 is a deficient number, since it is larger than the sum of its proper divisors (1).

257605531 is an equidigital number, since it uses as much as digits as its factorization.

257605531 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 31500, while the sum is 34.

The square root of 257605531 is about 16050.0944233983. The cubic root of 257605531 is about 636.2850625070.

The spelling of 257605531 in words is "two hundred fifty-seven million, six hundred five thousand, five hundred thirty-one".