6386637681 has 12 divisors (see below), whose sum is σ = 9225847540. Its totient is φ = 4257433440.

The previous prime is 6386637679. The next prime is 6386637683. The reversal of 6386637681 is 1867366836.

It is an interprime number because it is at equal distance from previous prime (6386637679) and next prime (6386637683).

It can be written as a sum of positive squares in 2 ways, for example, as 2044486656 + 4342151025 = 45216^2 + 65895^2 .

It is not a de Polignac number, because 6386637681 - 2¹ = 6386637679 is a prime.

It is a super-2 number, since 2×6386637681² = 81578281736738115522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6386637683) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 183711 + ... + 215691.

Almost surely, 2^6386637681 is an apocalyptic number.

It is an amenable number.

6386637681 is a deficient number, since it is larger than the sum of its proper divisors (2839209859).

6386637681 is a wasteful number, since it uses less digits than its factorization.

6386637681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54176 (or 54173 counting only the distinct ones).

The product of its digits is 5225472, while the sum is 54.

The square root of 6386637681 is about 79916.4418689921. The cubic root of 6386637681 is about 1855.3424999964.

The spelling of 6386637681 in words is "six billion, three hundred eighty-six million, six hundred thirty-seven thousand, six hundred eighty-one".