64138257 has 8 divisors (see below), whose sum is σ = 95019680. Its totient is φ = 42758820.

The previous prime is 64138253. The next prime is 64138259. The reversal of 64138257 is 75283146.

64138257 is a `hidden beast` number, since 641 + 3 + 8 + 2 + 5 + 7 = 666.

It is not a de Polignac number, because 64138257 - 2² = 64138253 is a prime.

It is a super-2 number, since 2×64138257² = 8227432021996098, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64138253) 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, 1187719 + ... + 1187772.

It is an arithmetic number, because the mean of its divisors is an integer number (11877460).

Almost surely, 2^64138257 is an apocalyptic number.

It is an amenable number.

64138257 is a deficient number, since it is larger than the sum of its proper divisors (30881423).

64138257 is a wasteful number, since it uses less digits than its factorization.

64138257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2375500 (or 2375494 counting only the distinct ones).

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

The square root of 64138257 is about 8008.6364007863. The cubic root of 64138257 is about 400.2878282542.

The spelling of 64138257 in words is "sixty-four million, one hundred thirty-eight thousand, two hundred fifty-seven".