66515694808 has 8 divisors (see below), whose sum is σ = 124716927780. Its totient is φ = 33257847400.

The previous prime is 66515694787. The next prime is 66515694811. The reversal of 66515694808 is 80849651566.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4157230918 + ... + 4157230933.

Almost surely, 2^66515694808 is an apocalyptic number.

It is an amenable number.

66515694808 is a deficient number, since it is larger than the sum of its proper divisors (58201232972).

66515694808 is a wasteful number, since it uses less digits than its factorization.

66515694808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8314461857 (or 8314461853 counting only the distinct ones).

The product of its (nonzero) digits is 12441600, while the sum is 58.

The spelling of 66515694808 in words is "sixty-six billion, five hundred fifteen million, six hundred ninety-four thousand, eight hundred eight".