3638690634681 has 80 divisors (see below), whose sum is σ = 5641653397248. Its totient is φ = 2335799980800.

The previous prime is 3638690634653. The next prime is 3638690634703. The reversal of 3638690634681 is 1864360968363.

It is a happy number.

3638690634681 is a `hidden beast` number, since 3 + 6 + 3 + 86 + 90 + 6 + 3 + 468 + 1 = 666.

3638690634681 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 3638690634681 - 2⁶ = 3638690634617 is a prime.

It is a super-2 number, since 2×3638690634681² (a number of 26 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (3638690634611) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 77924661 + ... + 77971341.

Almost surely, 2^{3638690634681} is an apocalyptic number.

It is an amenable number.

3638690634681 is a deficient number, since it is larger than the sum of its proper divisors (2002962762567).

3638690634681 is a wasteful number, since it uses less digits than its factorization.

3638690634681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47084 (or 47075 counting only the distinct ones).

The product of its (nonzero) digits is 80621568, while the sum is 63.

The spelling of 3638690634681 in words is "three trillion, six hundred thirty-eight billion, six hundred ninety million, six hundred thirty-four thousand, six hundred eighty-one".