665727264 has 36 divisors (see below), whose sum is σ = 1893162726. Its totient is φ = 221908992.

The previous prime is 665727241. The next prime is 665727281. The reversal of 665727264 is 462727566.

665727264 is a `hidden beast` number, since 6 + 6 + 572 + 72 + 6 + 4 = 666.

It can be written as a sum of positive squares in only one way, i.e., 542517264 + 123210000 = 23292^2 + 11100^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1155489 + ... + 1156064.

Almost surely, 2^665727264 is an apocalyptic number.

It is an amenable number.

665727264 is an abundant number, since it is smaller than the sum of its proper divisors (1227435462).

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

665727264 is a wasteful number, since it uses less digits than its factorization.

665727264 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2311569 (or 2311558 counting only the distinct ones).

The product of its digits is 846720, while the sum is 45.

The square root of 665727264 is about 25801.6911073674. The cubic root of 665727264 is about 873.1699499475.

The spelling of 665727264 in words is "six hundred sixty-five million, seven hundred twenty-seven thousand, two hundred sixty-four".