64815689920 has 56 divisors (see below), whose sum is σ = 154393568784. Its totient is φ = 25917674496.

The previous prime is 64815689903. The next prime is 64815689923. The reversal of 64815689920 is 2998651846.

It is not an unprimeable number, because it can be changed into a prime (64815689923) 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, 980142 + ... + 1044178.

It is an arithmetic number, because the mean of its divisors is an integer number (2757028014).

Almost surely, 2^64815689920 is an apocalyptic number.

It is an amenable number.

64815689920 is an abundant number, since it is smaller than the sum of its proper divisors (89577878864).

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

64815689920 is a wasteful number, since it uses less digits than its factorization.

64815689920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67217 (or 67207 counting only the distinct ones).

The product of its (nonzero) digits is 7464960, while the sum is 58.

The spelling of 64815689920 in words is "sixty-four billion, eight hundred fifteen million, six hundred eighty-nine thousand, nine hundred twenty".