664320771 has 20 divisors (see below), whose sum is σ = 993168000. Its totient is φ = 442529136.

The previous prime is 664320763. The next prime is 664320779. The reversal of 664320771 is 177023466.

664320771 is a `hidden beast` number, since 6 + 643 + 2 + 0 + 7 + 7 + 1 = 666.

664320771 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (664320763) and next prime (664320779).

It is not a de Polignac number, because 664320771 - 2³ = 664320763 is a prime.

It is not an unprimeable number, because it can be changed into a prime (664320779) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 136030 + ... + 140828.

It is an arithmetic number, because the mean of its divisors is an integer number (49658400).

Almost surely, 2^664320771 is an apocalyptic number.

664320771 is a deficient number, since it is larger than the sum of its proper divisors (328847229).

664320771 is a wasteful number, since it uses less digits than its factorization.

664320771 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6520 (or 6511 counting only the distinct ones).

The product of its (nonzero) digits is 42336, while the sum is 36.

The square root of 664320771 is about 25774.4208664327. The cubic root of 664320771 is about 872.5545961901.

The spelling of 664320771 in words is "six hundred sixty-four million, three hundred twenty thousand, seven hundred seventy-one".