6638244660 has 72 divisors (see below), whose sum is σ = 21320489736. Its totient is φ = 1666068480.

The previous prime is 6638244653. The next prime is 6638244689. The reversal of 6638244660 is 664428366.

6638244660 is a `hidden beast` number, since 6 + 638 + 2 + 4 + 4 + 6 + 6 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 1314207504 + 5324037156 = 36252^2 + 72966^2 .

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1081621 + ... + 1087740.

It is an arithmetic number, because the mean of its divisors is an integer number (296117913).

Almost surely, 2^6638244660 is an apocalyptic number.

6638244660 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

6638244660 is an abundant number, since it is smaller than the sum of its proper divisors (14682245076).

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

6638244660 is a wasteful number, since it uses less digits than its factorization.

6638244660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2169393 (or 2169388 counting only the distinct ones).

The product of its (nonzero) digits is 995328, while the sum is 45.

The square root of 6638244660 is about 81475.4236564622. The cubic root of 6638244660 is about 1879.3936346116.

The spelling of 6638244660 in words is "six billion, six hundred thirty-eight million, two hundred forty-four thousand, six hundred sixty".