665020979 has 8 divisors (see below), whose sum is σ = 764271360. Its totient is φ = 566832456.

The previous prime is 665020931. The next prime is 665020991. The reversal of 665020979 is 979020566.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 665020979 - 2⁸ = 665020723 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (665020079) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 264119 + ... + 266624.

It is an arithmetic number, because the mean of its divisors is an integer number (95533920).

Almost surely, 2^665020979 is an apocalyptic number.

665020979 is a deficient number, since it is larger than the sum of its proper divisors (99250381).

665020979 is a wasteful number, since it uses less digits than its factorization.

665020979 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 530929.

The product of its (nonzero) digits is 204120, while the sum is 44.

The square root of 665020979 is about 25788.0006786102. Note that the first 3 decimals coincide. The cubic root of 665020979 is about 872.8610521486.

The spelling of 665020979 in words is "six hundred sixty-five million, twenty thousand, nine hundred seventy-nine".