665979992 has 8 divisors (see below), whose sum is σ = 1248712500. Its totient is φ = 332989992.

The previous prime is 665979971. The next prime is 665980009. The reversal of 665979992 is 299979566.

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 pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41623742 + ... + 41623757.

Almost surely, 2^665979992 is an apocalyptic number.

It is an amenable number.

665979992 is a deficient number, since it is larger than the sum of its proper divisors (582732508).

665979992 is a wasteful number, since it uses less digits than its factorization.

665979992 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83247505 (or 83247501 counting only the distinct ones).

The product of its digits is 16533720, while the sum is 62.

The square root of 665979992 is about 25806.5881510904. The cubic root of 665979992 is about 873.2804289120.

The spelling of 665979992 in words is "six hundred sixty-five million, nine hundred seventy-nine thousand, nine hundred ninety-two".