257642513 has 2 divisors, whose sum is σ = 257642514. Its totient is φ = 257642512.

The previous prime is 257642491. The next prime is 257642521. The reversal of 257642513 is 315246752.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 243141649 + 14500864 = 15593^2 + 3808^2 .

It is a cyclic number.

It is not a de Polignac number, because 257642513 - 2²⁶ = 190533649 is a prime.

It is not a weakly prime, because it can be changed into another prime (257642533) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128821256 + 128821257.

It is an arithmetic number, because the mean of its divisors is an integer number (128821257).

Almost surely, 2^257642513 is an apocalyptic number.

It is an amenable number.

257642513 is a deficient number, since it is larger than the sum of its proper divisors (1).

257642513 is an equidigital number, since it uses as much as digits as its factorization.

257642513 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 50400, while the sum is 35.

The square root of 257642513 is about 16051.2464625025. The cubic root of 257642513 is about 636.3155095348.

The spelling of 257642513 in words is "two hundred fifty-seven million, six hundred forty-two thousand, five hundred thirteen".