66656772 has 72 divisors (see below), whose sum is σ = 207386816. Its totient is φ = 17578944.

The previous prime is 66656767. The next prime is 66656791. The reversal of 66656772 is 27765666.

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, 6898 + ... + 13449.

Almost surely, 2^66656772 is an apocalyptic number.

It is an amenable number.

66656772 is an abundant number, since it is smaller than the sum of its proper divisors (140730044).

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

66656772 is a wasteful number, since it uses less digits than its factorization.

66656772 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20377 (or 20372 counting only the distinct ones).

The product of its digits is 635040, while the sum is 45.

The square root of 66656772 is about 8164.3598646801. The cubic root of 66656772 is about 405.4600715919.

The spelling of 66656772 in words is "sixty-six million, six hundred fifty-six thousand, seven hundred seventy-two".