665697917 has 12 divisors (see below), whose sum is σ = 717142176. Its totient is φ = 617695680.

The previous prime is 665697913. The next prime is 665697919. The reversal of 665697917 is 719796566.

It is not a de Polignac number, because 665697917 - 2² = 665697913 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665697913) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4298 + ... + 36740.

It is an arithmetic number, because the mean of its divisors is an integer number (59761848).

Almost surely, 2^665697917 is an apocalyptic number.

It is an amenable number.

665697917 is a deficient number, since it is larger than the sum of its proper divisors (51444259).

665697917 is a wasteful number, since it uses less digits than its factorization.

665697917 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32548 (or 32531 counting only the distinct ones).

The product of its digits is 4286520, while the sum is 56.

The square root of 665697917 is about 25801.1223980663. The cubic root of 665697917 is about 873.1571192201.

The spelling of 665697917 in words is "six hundred sixty-five million, six hundred ninety-seven thousand, nine hundred seventeen".