63644004 has 18 divisors (see below), whose sum is σ = 160877990. Its totient is φ = 21214656.

The previous prime is 63643927. The next prime is 63644011. The reversal of 63644004 is 40044636.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 44195904 + 19448100 = 6648^2 + 4410^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 883909 + ... + 883980.

Almost surely, 2^63644004 is an apocalyptic number.

It is an amenable number.

63644004 is an abundant number, since it is smaller than the sum of its proper divisors (97233986).

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

63644004 is a wasteful number, since it uses less digits than its factorization.

63644004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1767899 (or 1767894 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 27.

The square root of 63644004 is about 7977.7192229358. The cubic root of 63644004 is about 399.2569622586.

The spelling of 63644004 in words is "sixty-three million, six hundred forty-four thousand, four".