64400856 has 32 divisors (see below), whose sum is σ = 173387760. Its totient is φ = 19815552.

The previous prime is 64400849. The next prime is 64400863. The reversal of 64400856 is 65800446.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (64400849) and next prime (64400863).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 102895 + ... + 103518.

Almost surely, 2^64400856 is an apocalyptic number.

It is an amenable number.

64400856 is an abundant number, since it is smaller than the sum of its proper divisors (108986904).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

64400856 is a wasteful number, since it uses less digits than its factorization.

64400856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 206435 (or 206431 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 33.

The square root of 64400856 is about 8025.0143925105. The cubic root of 64400856 is about 400.8333791588.

It can be divided in two parts, 64400 and 856, that added together give a palindrome (65256).

The spelling of 64400856 in words is "sixty-four million, four hundred thousand, eight hundred fifty-six".