64220865920 has 64 divisors (see below), whose sum is σ = 153559551600. Its totient is φ = 25683068928.

The previous prime is 64220865889. The next prime is 64220865937. The reversal of 64220865920 is 2956802246.

It is a tau number, because it is divible by the number of its divisors (64).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5034911 + ... + 5047649.

Almost surely, 2^64220865920 is an apocalyptic number.

It is an amenable number.

64220865920 is an abundant number, since it is smaller than the sum of its proper divisors (89338685680).

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

64220865920 is a wasteful number, since it uses less digits than its factorization.

64220865920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20635 (or 20623 counting only the distinct ones).

The product of its (nonzero) digits is 414720, while the sum is 44.

The spelling of 64220865920 in words is "sixty-four billion, two hundred twenty million, eight hundred sixty-five thousand, nine hundred twenty".