665746568 has 64 divisors (see below), whose sum is σ = 1306931760. Its totient is φ = 317730816.

The previous prime is 665746553. The next prime is 665746633. The reversal of 665746568 is 865647566.

It can be written as a sum of positive squares in 8 ways, for example, as 389588644 + 276157924 = 19738^2 + 16618^2 .

It is a Harshad number since it is a multiple of its sum of digits (53).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4240346 + ... + 4240502.

Almost surely, 2^665746568 is an apocalyptic number.

It is an amenable number.

665746568 is a deficient number, since it is larger than the sum of its proper divisors (641185192).

665746568 is a wasteful number, since it uses less digits than its factorization.

665746568 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 426 (or 422 counting only the distinct ones).

The product of its digits is 7257600, while the sum is 53.

The square root of 665746568 is about 25802.0651886627. The cubic root of 665746568 is about 873.1783895947.

The spelling of 665746568 in words is "six hundred sixty-five million, seven hundred forty-six thousand, five hundred sixty-eight".