664636836 has 12 divisors (see below), whose sum is σ = 1550819312. Its totient is φ = 221545608.

The previous prime is 664636799. The next prime is 664636837. The reversal of 664636836 is 638636466.

It is a tau number, because it is divible by the number of its divisors (12).

It is not an unprimeable number, because it can be changed into a prime (664636837) 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, 27693190 + ... + 27693213.

Almost surely, 2^664636836 is an apocalyptic number.

It is an amenable number.

664636836 is an abundant number, since it is smaller than the sum of its proper divisors (886182476).

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

664636836 is a wasteful number, since it uses less digits than its factorization.

664636836 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55386410 (or 55386408 counting only the distinct ones).

The product of its digits is 2239488, while the sum is 48.

The square root of 664636836 is about 25780.5515069015. The cubic root of 664636836 is about 872.6929531683.

The spelling of 664636836 in words is "six hundred sixty-four million, six hundred thirty-six thousand, eight hundred thirty-six".