664133638 has 16 divisors (see below), whose sum is σ = 1198437120. Its totient is φ = 269648136.

The previous prime is 664133627. The next prime is 664133719. The reversal of 664133638 is 836331466.

It is a self number, because there is not a number n which added to its sum of digits gives 664133638.

It is a congruent number.

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 7 ways as a sum of consecutive naturals, for example, 1248106 + ... + 1248637.

It is an arithmetic number, because the mean of its divisors is an integer number (74902320).

Almost surely, 2^664133638 is an apocalyptic number.

664133638 is a deficient number, since it is larger than the sum of its proper divisors (534303482).

664133638 is a wasteful number, since it uses less digits than its factorization.

664133638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2496771.

The product of its digits is 186624, while the sum is 40.

The square root of 664133638 is about 25770.7904030901. The cubic root of 664133638 is about 872.4726583168.

The spelling of 664133638 in words is "six hundred sixty-four million, one hundred thirty-three thousand, six hundred thirty-eight".