665707716 has 18 divisors (see below), whose sum is σ = 1682761262. Its totient is φ = 221902560.

The previous prime is 665707697. The next prime is 665707727. The reversal of 665707716 is 617707566.

665707716 is a `hidden beast` number, since 6 + 6 + 570 + 7 + 71 + 6 = 666.

It can be written as a sum of positive squares in only one way, i.e., 593117316 + 72590400 = 24354^2 + 8520^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 9245905 + ... + 9245976.

Almost surely, 2^665707716 is an apocalyptic number.

It is an amenable number.

665707716 is an abundant number, since it is smaller than the sum of its proper divisors (1017053546).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

665707716 is a wasteful number, since it uses less digits than its factorization.

665707716 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18491891 (or 18491886 counting only the distinct ones).

The product of its (nonzero) digits is 370440, while the sum is 45.

The square root of 665707716 is about 25801.3122922072. The cubic root of 665707716 is about 873.1614034580.

The spelling of 665707716 in words is "six hundred sixty-five million, seven hundred seven thousand, seven hundred sixteen".