64813257 has 16 divisors (see below), whose sum is σ = 96159360. Its totient is φ = 43146000.

The previous prime is 64813249. The next prime is 64813261. The reversal of 64813257 is 75231846.

64813257 is a `hidden beast` number, since 648 + 1 + 3 + 2 + 5 + 7 = 666.

It is not a de Polignac number, because 64813257 - 2³ = 64813249 is a prime.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (64813207) 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, 24132 + ... + 26682.

It is an arithmetic number, because the mean of its divisors is an integer number (6009960).

Almost surely, 2^64813257 is an apocalyptic number.

It is an amenable number.

64813257 is a deficient number, since it is larger than the sum of its proper divisors (31346103).

64813257 is a wasteful number, since it uses less digits than its factorization.

64813257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3501 (or 3495 counting only the distinct ones).

The product of its digits is 40320, while the sum is 36.

The square root of 64813257 is about 8050.6681089211. The cubic root of 64813257 is about 401.6871591465.

The spelling of 64813257 in words is "sixty-four million, eight hundred thirteen thousand, two hundred fifty-seven".