257664715 has 32 divisors (see below), whose sum is σ = 397946880. Its totient is φ = 155433600.

The previous prime is 257664713. The next prime is 257664731. The reversal of 257664715 is 517466752.

It is not a de Polignac number, because 257664715 - 2¹ = 257664713 is a prime.

It is a super-2 number, since 2×257664715² = 132782210712062450, which contains 22 as substring.

It is a Smith number, since the sum of its digits (43) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (257664713) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1141 + ... + 22729.

It is an arithmetic number, because the mean of its divisors is an integer number (12435840).

Almost surely, 2^257664715 is an apocalyptic number.

257664715 is a deficient number, since it is larger than the sum of its proper divisors (140282165).

257664715 is a wasteful number, since it uses less digits than its factorization.

257664715 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21643.

The product of its digits is 352800, while the sum is 43.

The square root of 257664715 is about 16051.9380449839. The cubic root of 257664715 is about 636.3337868899. Note that the first 3 decimals are identical.

The spelling of 257664715 in words is "two hundred fifty-seven million, six hundred sixty-four thousand, seven hundred fifteen".