666657720886 has 4 divisors (see below), whose sum is σ = 999986581332. Its totient is φ = 333328860442.

The previous prime is 666657720857. The next prime is 666657720977. The reversal of 666657720886 is 688027756666.

It is a semiprime because it is the product of two primes.

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, 166664430220 + ... + 166664430223.

It is an arithmetic number, because the mean of its divisors is an integer number (249996645333).

Almost surely, 2^666657720886 is an apocalyptic number.

666657720886 is a deficient number, since it is larger than the sum of its proper divisors (333328860446).

666657720886 is a wasteful number, since it uses less digits than its factorization.

666657720886 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 333328860445.

The product of its (nonzero) digits is 243855360, while the sum is 67.

The spelling of 666657720886 in words is "six hundred sixty-six billion, six hundred fifty-seven million, seven hundred twenty thousand, eight hundred eighty-six".