77993578664 has 16 divisors (see below), whose sum is σ = 147745569300. Its totient is φ = 38594760192.

The previous prime is 77993578643. The next prime is 77993578679. The reversal of 77993578664 is 46687539977.

It can be written as a sum of positive squares in 2 ways, for example, as 76871998564 + 1121580100 = 277258^2 + 33490^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 50252819 + ... + 50254370.

Almost surely, 2^77993578664 is an apocalyptic number.

It is an amenable number.

77993578664 is a deficient number, since it is larger than the sum of its proper divisors (69751990636).

77993578664 is a wasteful number, since it uses less digits than its factorization.

77993578664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 100507292 (or 100507288 counting only the distinct ones).

The product of its digits is 480090240, while the sum is 71.

The spelling of 77993578664 in words is "seventy-seven billion, nine hundred ninety-three million, five hundred seventy-eight thousand, six hundred sixty-four".