665242664 has 8 divisors (see below), whose sum is σ = 1247330010. Its totient is φ = 332621328.

The previous prime is 665242651. The next prime is 665242679. The reversal of 665242664 is 466242566.

It can be written as a sum of positive squares in only one way, i.e., 662650564 + 2592100 = 25742^2 + 1610^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41577659 + ... + 41577674.

Almost surely, 2^665242664 is an apocalyptic number.

It is an amenable number.

665242664 is a deficient number, since it is larger than the sum of its proper divisors (582087346).

665242664 is a wasteful number, since it uses less digits than its factorization.

665242664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83155339 (or 83155335 counting only the distinct ones).

The product of its digits is 414720, while the sum is 41.

The square root of 665242664 is about 25792.2985404558. The cubic root of 665242664 is about 872.9580308963.

The spelling of 665242664 in words is "six hundred sixty-five million, two hundred forty-two thousand, six hundred sixty-four".