257536813 has 2 divisors, whose sum is σ = 257536814. Its totient is φ = 257536812.

The previous prime is 257536777. The next prime is 257536841. The reversal of 257536813 is 318635752.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 248283049 + 9253764 = 15757^2 + 3042^2 .

It is a cyclic number.

It is not a de Polignac number, because 257536813 - 2²¹ = 255439661 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (257536883) 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, 128768406 + 128768407.

It is an arithmetic number, because the mean of its divisors is an integer number (128768407).

Almost surely, 2^257536813 is an apocalyptic number.

It is an amenable number.

257536813 is a deficient number, since it is larger than the sum of its proper divisors (1).

257536813 is an equidigital number, since it uses as much as digits as its factorization.

257536813 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 151200, while the sum is 40.

The square root of 257536813 is about 16047.9535455459. The cubic root of 257536813 is about 636.2284797087.

The spelling of 257536813 in words is "two hundred fifty-seven million, five hundred thirty-six thousand, eight hundred thirteen".