665072917 has 2 divisors, whose sum is σ = 665072918. Its totient is φ = 665072916.

The previous prime is 665072909. The next prime is 665072927. The reversal of 665072917 is 719270566.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 569013316 + 96059601 = 23854^2 + 9801^2 .

It is a cyclic number.

It is not a de Polignac number, because 665072917 - 2³ = 665072909 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (665072927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332536458 + 332536459.

It is an arithmetic number, because the mean of its divisors is an integer number (332536459).

Almost surely, 2^665072917 is an apocalyptic number.

It is an amenable number.

665072917 is a deficient number, since it is larger than the sum of its proper divisors (1).

665072917 is an equidigital number, since it uses as much as digits as its factorization.

665072917 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 158760, while the sum is 43.

The square root of 665072917 is about 25789.0076776909. The cubic root of 665072917 is about 872.8837749792.

The spelling of 665072917 in words is "six hundred sixty-five million, seventy-two thousand, nine hundred seventeen".