257485817 has 2 divisors, whose sum is σ = 257485818. Its totient is φ = 257485816.

The previous prime is 257485799. The next prime is 257485841. The reversal of 257485817 is 718584752.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 152300281 + 105185536 = 12341^2 + 10256^2 .

It is a cyclic number.

It is not a de Polignac number, because 257485817 - 2⁸ = 257485561 is a prime.

It is not a weakly prime, because it can be changed into another prime (257485117) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128742908 + 128742909.

It is an arithmetic number, because the mean of its divisors is an integer number (128742909).

Almost surely, 2^257485817 is an apocalyptic number.

It is an amenable number.

257485817 is a deficient number, since it is larger than the sum of its proper divisors (1).

257485817 is an equidigital number, since it uses as much as digits as its factorization.

257485817 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 627200, while the sum is 47.

The square root of 257485817 is about 16046.3646038597. The cubic root of 257485817 is about 636.1864828010.

The spelling of 257485817 in words is "two hundred fifty-seven million, four hundred eighty-five thousand, eight hundred seventeen".