257664407 has 16 divisors (see below), whose sum is σ = 345956352. Its totient is φ = 185332320.

The previous prime is 257664403. The next prime is 257664409. The reversal of 257664407 is 704466752.

It is a cyclic number.

It is not a de Polignac number, because 257664407 - 2² = 257664403 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (257664401) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 127703 + ... + 129704.

It is an arithmetic number, because the mean of its divisors is an integer number (21622272).

Almost surely, 2^257664407 is an apocalyptic number.

257664407 is a deficient number, since it is larger than the sum of its proper divisors (88291945).

257664407 is a wasteful number, since it uses less digits than its factorization.

257664407 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 257438.

The product of its (nonzero) digits is 282240, while the sum is 41.

The square root of 257664407 is about 16051.9284511239. The cubic root of 257664407 is about 636.3335333422. Note that the first 3 decimals are identical.

The spelling of 257664407 in words is "two hundred fifty-seven million, six hundred sixty-four thousand, four hundred seven".