257317657 has 4 divisors (see below), whose sum is σ = 258624036. Its totient is φ = 256011280.

The previous prime is 257317649. The next prime is 257317727. The reversal of 257317657 is 756713752.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 248251536 + 9066121 = 15756^2 + 3011^2 .

It is a cyclic number.

It is not a de Polignac number, because 257317657 - 2³ = 257317649 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (257317607) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 652894 + ... + 653287.

It is an arithmetic number, because the mean of its divisors is an integer number (64656009).

Almost surely, 2^257317657 is an apocalyptic number.

It is an amenable number.

257317657 is a deficient number, since it is larger than the sum of its proper divisors (1306379).

257317657 is a wasteful number, since it uses less digits than its factorization.

257317657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1306378.

The product of its digits is 308700, while the sum is 43.

The square root of 257317657 is about 16041.1239319444. The cubic root of 257317657 is about 636.0479581269.

The spelling of 257317657 in words is "two hundred fifty-seven million, three hundred seventeen thousand, six hundred fifty-seven".