6640644404 has 12 divisors (see below), whose sum is σ = 11622088128. Its totient is φ = 3320047800.

The previous prime is 6640644401. The next prime is 6640644407. The reversal of 6640644404 is 4044460466.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (6640644401) and next prime (6640644407).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6640644401) 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, 8252 + ... + 115539.

It is an arithmetic number, because the mean of its divisors is an integer number (968507344).

Almost surely, 2^6640644404 is an apocalyptic number.

It is an amenable number.

6640644404 is a deficient number, since it is larger than the sum of its proper divisors (4981443724).

6640644404 is a wasteful number, since it uses less digits than its factorization.

6640644404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137206 (or 137204 counting only the distinct ones).

The product of its (nonzero) digits is 221184, while the sum is 38.

The square root of 6640644404 is about 81490.1491224553. The cubic root of 6640644404 is about 1879.6200760115.

The spelling of 6640644404 in words is "six billion, six hundred forty million, six hundred forty-four thousand, four hundred four".