665716664 has 16 divisors (see below), whose sum is σ = 1248728400. Its totient is φ = 332722432.

The previous prime is 665716643. The next prime is 665716687. The reversal of 665716664 is 466617566.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5597 + ... + 36915.

It is an arithmetic number, because the mean of its divisors is an integer number (78045525).

Almost surely, 2^665716664 is an apocalyptic number.

It is an amenable number.

665716664 is a deficient number, since it is larger than the sum of its proper divisors (583011736).

665716664 is a wasteful number, since it uses less digits than its factorization.

665716664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33982 (or 33978 counting only the distinct ones).

The product of its digits is 1088640, while the sum is 47.

The square root of 665716664 is about 25801.4856936573. The cubic root of 665716664 is about 873.1653155919.

The spelling of 665716664 in words is "six hundred sixty-five million, seven hundred sixteen thousand, six hundred sixty-four".