64721968872 has 64 divisors (see below), whose sum is σ = 179844960960. Its totient is φ = 19242662400.

The previous prime is 64721968859. The next prime is 64721968901. The reversal of 64721968872 is 27886912746.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2298829 + ... + 2326812.

It is an arithmetic number, because the mean of its divisors is an integer number (2810077515).

Almost surely, 2^64721968872 is an apocalyptic number.

It is an amenable number.

64721968872 is an abundant number, since it is smaller than the sum of its proper divisors (115122992088).

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

64721968872 is a wasteful number, since it uses less digits than its factorization.

64721968872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4625714 (or 4625710 counting only the distinct ones).

The product of its digits is 16257024, while the sum is 60.

The spelling of 64721968872 in words is "sixty-four billion, seven hundred twenty-one million, nine hundred sixty-eight thousand, eight hundred seventy-two".