6638876866 has 8 divisors (see below), whose sum is σ = 10201201164. Its totient is φ = 3238476480.

The previous prime is 6638876833. The next prime is 6638876879. The reversal of 6638876866 is 6686788366.

It can be written as a sum of positive squares in 2 ways, for example, as 6395360841 + 243516025 = 79971^2 + 15605^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 6638876798 and 6638876807.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 40480875 + ... + 40481038.

Almost surely, 2^6638876866 is an apocalyptic number.

6638876866 is a deficient number, since it is larger than the sum of its proper divisors (3562324298).

6638876866 is a wasteful number, since it uses less digits than its factorization.

6638876866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80961956.

The product of its digits is 83607552, while the sum is 64.

The square root of 6638876866 is about 81479.3032984451. The cubic root of 6638876866 is about 1879.4532952737.

The spelling of 6638876866 in words is "six billion, six hundred thirty-eight million, eight hundred seventy-six thousand, eight hundred sixty-six".