636761687331 has 32 divisors (see below), whose sum is σ = 1120778408448. Its totient is φ = 311327331840.

The previous prime is 636761687281. The next prime is 636761687357. The reversal of 636761687331 is 133786167636.

It is not a de Polignac number, because 636761687331 - 2⁷ = 636761687203 is a prime.

It is a super-2 number, since 2×636761687331² (a number of 24 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (57) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (636761687371) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 81070900 + ... + 81078753.

It is an arithmetic number, because the mean of its divisors is an integer number (35024325264).

Almost surely, 2^636761687331 is an apocalyptic number.

636761687331 is a deficient number, since it is larger than the sum of its proper divisors (484016721117).

636761687331 is a wasteful number, since it uses less digits than its factorization.

636761687331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 162149691.

The product of its digits is 13716864, while the sum is 57.

The spelling of 636761687331 in words is "six hundred thirty-six billion, seven hundred sixty-one million, six hundred eighty-seven thousand, three hundred thirty-one".