6644738736 has 60 divisors (see below), whose sum is σ = 18675945288. Its totient is φ = 2205395712.

The previous prime is 6644738707. The next prime is 6644738827. The reversal of 6644738736 is 6378374466.

It is a happy number.

6644738736 is a `hidden beast` number, since 6 + 64 + 473 + 87 + 36 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 65470 + ... + 132573.

Almost surely, 2^6644738736 is an apocalyptic number.

It is an amenable number.

6644738736 is an abundant number, since it is smaller than the sum of its proper divisors (12031206552).

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

6644738736 is a wasteful number, since it uses less digits than its factorization.

6644738736 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 198290 (or 198281 counting only the distinct ones).

The product of its digits is 12192768, while the sum is 54.

The square root of 6644738736 is about 81515.2668890926. The cubic root of 6644738736 is about 1880.0062939279.

The spelling of 6644738736 in words is "six billion, six hundred forty-four million, seven hundred thirty-eight thousand, seven hundred thirty-six".