66164700625 has 15 divisors (see below), whose sum is σ = 82687446391. Its totient is φ = 52926616000.

The previous prime is 66164700607. The next prime is 66164700631. The reversal of 66164700625 is 52600746166.

It is a happy number.

The square root of 66164700625 is 257225.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 7 ways, for example, as 22373278929 + 43791421696 = 149577^2 + 209264^2 .

It is not a de Polignac number, because 66164700625 - 2⁵ = 66164700593 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 6425481 + ... + 6435769.

Almost surely, 2^66164700625 is an apocalyptic number.

66164700625 is the 257225-th square number.

66164700625 is the 128613-rd centered octagonal number.

It is an amenable number.

66164700625 is a deficient number, since it is larger than the sum of its proper divisors (16522745766).

66164700625 is an frugal number, since it uses more digits than its factorization.

66164700625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20598 (or 10294 counting only the distinct ones).

The product of its (nonzero) digits is 362880, while the sum is 43.

The spelling of 66164700625 in words is "sixty-six billion, one hundred sixty-four million, seven hundred thousand, six hundred twenty-five".