66900639136 has 24 divisors (see below), whose sum is σ = 131841232740. Its totient is φ = 33417151488.

The previous prime is 66900639109. The next prime is 66900639137. The reversal of 66900639136 is 63193600966.

It can be written as a sum of positive squares in 2 ways, for example, as 66896718736 + 3920400 = 258644^2 + 1980^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 66900639136.

It is not an unprimeable number, because it can be changed into a prime (66900639137) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1003711 + ... + 1068286.

Almost surely, 2^66900639136 is an apocalyptic number.

It is an amenable number.

66900639136 is a deficient number, since it is larger than the sum of its proper divisors (64940593604).

66900639136 is a wasteful number, since it uses less digits than its factorization.

66900639136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2073016 (or 2073008 counting only the distinct ones).

The product of its (nonzero) digits is 944784, while the sum is 49.

The spelling of 66900639136 in words is "sixty-six billion, nine hundred million, six hundred thirty-nine thousand, one hundred thirty-six".