664916657 has 4 divisors (see below), whose sum is σ = 667370496. Its totient is φ = 662462820.

The previous prime is 664916627. The next prime is 664916663. The reversal of 664916657 is 756619466.

664916657 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 664916657 - 2⁸ = 664916401 is a prime.

It is a super-2 number, since 2×664916657² = 884228321512111298, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (664916627) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1226513 + ... + 1227054.

It is an arithmetic number, because the mean of its divisors is an integer number (166842624).

Almost surely, 2^664916657 is an apocalyptic number.

It is an amenable number.

664916657 is a deficient number, since it is larger than the sum of its proper divisors (2453839).

664916657 is a wasteful number, since it uses less digits than its factorization.

664916657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2453838.

The product of its digits is 1632960, while the sum is 50.

The square root of 664916657 is about 25785.9779143627. The cubic root of 664916657 is about 872.8154077878.

The spelling of 664916657 in words is "six hundred sixty-four million, nine hundred sixteen thousand, six hundred fifty-seven".