86991636681 has 12 divisors (see below), whose sum is σ = 125742659952. Its totient is φ = 57953775096.

The previous prime is 86991636643. The next prime is 86991636773. The reversal of 86991636681 is 18663619968.

It is not a de Polignac number, because 86991636681 - 2⁶ = 86991636617 is a prime.

It is a super-2 number, since 2×86991636681² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (86991636181) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3373891 + ... + 3399576.

It is an arithmetic number, because the mean of its divisors is an integer number (10478554996).

Almost surely, 2^86991636681 is an apocalyptic number.

It is an amenable number.

86991636681 is a deficient number, since it is larger than the sum of its proper divisors (38751023271).

86991636681 is a wasteful number, since it uses less digits than its factorization.

86991636681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6774900 (or 6774897 counting only the distinct ones).

The product of its digits is 20155392, while the sum is 63.

The spelling of 86991636681 in words is "eighty-six billion, nine hundred ninety-one million, six hundred thirty-six thousand, six hundred eighty-one".