66565715620 has 12 divisors (see below), whose sum is σ = 139788002844. Its totient is φ = 26626286240.

The previous prime is 66565715609. The next prime is 66565715653. The reversal of 66565715620 is 2651756566.

It can be written as a sum of positive squares in 2 ways, for example, as 25245396544 + 41320319076 = 158888^2 + 203274^2 .

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, 1664142871 + ... + 1664142910.

It is an arithmetic number, because the mean of its divisors is an integer number (11649000237).

Almost surely, 2^66565715620 is an apocalyptic number.

It is an amenable number.

66565715620 is an abundant number, since it is smaller than the sum of its proper divisors (73222287224).

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

66565715620 is a wasteful number, since it uses less digits than its factorization.

66565715620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3328285790 (or 3328285788 counting only the distinct ones).

The product of its (nonzero) digits is 2268000, while the sum is 49.

The spelling of 66565715620 in words is "sixty-six billion, five hundred sixty-five million, seven hundred fifteen thousand, six hundred twenty".