664611856 has 40 divisors (see below), whose sum is σ = 1311103584. Its totient is φ = 326304000.

The previous prime is 664611847. The next prime is 664611859. The reversal of 664611856 is 658116466.

It is a Smith number, since the sum of its digits (43) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (664611859) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 292035 + ... + 294301.

Almost surely, 2^664611856 is an apocalyptic number.

It is an amenable number.

664611856 is a deficient number, since it is larger than the sum of its proper divisors (646491728).

664611856 is a wasteful number, since it uses less digits than its factorization.

664611856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2599 (or 2593 counting only the distinct ones).

The product of its digits is 207360, while the sum is 43.

The square root of 664611856 is about 25780.0670286173. The cubic root of 664611856 is about 872.6820198074.

The spelling of 664611856 in words is "six hundred sixty-four million, six hundred eleven thousand, eight hundred fifty-six".