64640396400 has 120 divisors (see below), whose sum is σ = 207127312944. Its totient is φ = 17232230400.

The previous prime is 64640396393. The next prime is 64640396453. The reversal of 64640396400 is 469304646.

64640396400 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (120).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5539372 + ... + 5551028.

Almost surely, 2^64640396400 is an apocalyptic number.

64640396400 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

64640396400 is an abundant number, since it is smaller than the sum of its proper divisors (142486916544).

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

64640396400 is a wasteful number, since it uses less digits than its factorization.

64640396400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16299 (or 16288 counting only the distinct ones).

The product of its (nonzero) digits is 373248, while the sum is 42.

The spelling of 64640396400 in words is "sixty-four billion, six hundred forty million, three hundred ninety-six thousand, four hundred".