66605891152788 has 144 divisors (see below), whose sum is σ = 181529114392080. Its totient is φ = 20470050551808.

The previous prime is 66605891152769. The next prime is 66605891152901. The reversal of 66605891152788 is 88725119850666.

It can be written as a sum of positive squares in 8 ways, for example, as 63075317904 + 66542815834884 = 251148^2 + 8157378^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1445636920 + ... + 1445682992.

It is an arithmetic number, because the mean of its divisors is an integer number (1260618849945).

Almost surely, 2^{66605891152788} is an apocalyptic number.

It is an amenable number.

66605891152788 is an abundant number, since it is smaller than the sum of its proper divisors (114923223239292).

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

66605891152788 is a wasteful number, since it uses less digits than its factorization.

66605891152788 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49658 (or 49653 counting only the distinct ones).

The product of its (nonzero) digits is 348364800, while the sum is 72.

The spelling of 66605891152788 in words is "sixty-six trillion, six hundred five billion, eight hundred ninety-one million, one hundred fifty-two thousand, seven hundred eighty-eight".