257326813 has 2 divisors, whose sum is σ = 257326814. Its totient is φ = 257326812.

The previous prime is 257326787. The next prime is 257326847. The reversal of 257326813 is 318623752.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 232196644 + 25130169 = 15238^2 + 5013^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-257326813 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (257326513) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128663406 + 128663407.

It is an arithmetic number, because the mean of its divisors is an integer number (128663407).

Almost surely, 2^257326813 is an apocalyptic number.

It is an amenable number.

257326813 is a deficient number, since it is larger than the sum of its proper divisors (1).

257326813 is an equidigital number, since it uses as much as digits as its factorization.

257326813 is an evil number, because the sum of its binary digits is even.

The product of its digits is 60480, while the sum is 37.

The square root of 257326813 is about 16041.4093208795. The cubic root of 257326813 is about 636.0555020917.

The spelling of 257326813 in words is "two hundred fifty-seven million, three hundred twenty-six thousand, eight hundred thirteen".