257685681 has 8 divisors (see below), whose sum is σ = 374815584. Its totient is φ = 156173120.

The previous prime is 257685679. The next prime is 257685689. The reversal of 257685681 is 186586752.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 257685681 - 2¹ = 257685679 is a prime.

It is a super-2 number, since 2×257685681² = 132803820384867522, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 257685681.

It is not an unprimeable number, because it can be changed into a prime (257685689) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3904296 + ... + 3904361.

It is an arithmetic number, because the mean of its divisors is an integer number (46851948).

Almost surely, 2^257685681 is an apocalyptic number.

It is an amenable number.

257685681 is a deficient number, since it is larger than the sum of its proper divisors (117129903).

257685681 is a wasteful number, since it uses less digits than its factorization.

257685681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7808671.

The product of its digits is 806400, while the sum is 48.

The square root of 257685681 is about 16052.5910992587. The cubic root of 257685681 is about 636.3510457688.

The spelling of 257685681 in words is "two hundred fifty-seven million, six hundred eighty-five thousand, six hundred eighty-one".