6400634864 has 20 divisors (see below), whose sum is σ = 13355171256. Its totient is φ = 2954139072.

The previous prime is 6400634843. The next prime is 6400634939. The reversal of 6400634864 is 4684360046.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15385934 + ... + 15386349.

Almost surely, 2^6400634864 is an apocalyptic number.

It is an amenable number.

6400634864 is an abundant number, since it is smaller than the sum of its proper divisors (6954536392).

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

6400634864 is a wasteful number, since it uses less digits than its factorization.

6400634864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30772304 (or 30772298 counting only the distinct ones).

The product of its (nonzero) digits is 331776, while the sum is 41.

The square root of 6400634864 is about 80003.9678016034. The cubic root of 6400634864 is about 1856.6969226164.

The spelling of 6400634864 in words is "six billion, four hundred million, six hundred thirty-four thousand, eight hundred sixty-four".