6638875668 has 72 divisors (see below), whose sum is σ = 17445748320. Its totient is φ = 2207541600.

The previous prime is 6638875577. The next prime is 6638875729. The reversal of 6638875668 is 8665788366.

6638875668 is a `hidden beast` number, since 6 + 63 + 8 + 8 + 7 + 566 + 8 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 399118 + ... + 415418.

It is an arithmetic number, because the mean of its divisors is an integer number (242302060).

Almost surely, 2^6638875668 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6638875668, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8722874160).

6638875668 is an abundant number, since it is smaller than the sum of its proper divisors (10806872652).

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

6638875668 is a wasteful number, since it uses less digits than its factorization.

6638875668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16739 (or 16725 counting only the distinct ones).

The product of its digits is 69672960, while the sum is 63.

The square root of 6638875668 is about 81479.2959468846. The cubic root of 6638875668 is about 1879.4531822232.

The spelling of 6638875668 in words is "six billion, six hundred thirty-eight million, eight hundred seventy-five thousand, six hundred sixty-eight".