665136320 has 28 divisors (see below), whose sum is σ = 1583856624. Its totient is φ = 266054400.

The previous prime is 665136319. The next prime is 665136337. The reversal of 665136320 is 23631566.

It is a Harshad number since it is a multiple of its sum of digits (32).

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 3 ways as a sum of consecutive naturals, for example, 1038956 + ... + 1039595.

It is an arithmetic number, because the mean of its divisors is an integer number (56566308).

Almost surely, 2^665136320 is an apocalyptic number.

It is an amenable number.

665136320 is an abundant number, since it is smaller than the sum of its proper divisors (918720304).

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

665136320 is a wasteful number, since it uses less digits than its factorization.

665136320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2078568 (or 2078558 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 32.

The square root of 665136320 is about 25790.2369124442. The cubic root of 665136320 is about 872.9115121341.

Adding to 665136320 its reverse (23631566), we get a palindrome (688767886).

The spelling of 665136320 in words is "six hundred sixty-five million, one hundred thirty-six thousand, three hundred twenty".