66666593988 has 36 divisors (see below), whose sum is σ = 168564924528. Its totient is φ = 22216054320.

The previous prime is 66666593971. The next prime is 66666593999. The reversal of 66666593988 is 88939566666.

It is a tau number, because it is divible by the number of its divisors (36).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 123018 + ... + 385313.

Almost surely, 2^66666593988 is an apocalyptic number.

It is an amenable number.

66666593988 is an abundant number, since it is smaller than the sum of its proper divisors (101898330540).

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

66666593988 is a wasteful number, since it uses less digits than its factorization.

66666593988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 511984 (or 511979 counting only the distinct ones).

The product of its digits is 604661760, while the sum is 72.

The spelling of 66666593988 in words is "sixty-six billion, six hundred sixty-six million, five hundred ninety-three thousand, nine hundred eighty-eight".