91639437976801 has 27 divisors (see below), whose sum is σ = 109073578145427. Its totient is φ = 76899078930960.

The previous prime is 91639437976777. The next prime is 91639437976829. The reversal of 91639437976801 is 10867973493619.

The square root of 91639437976801 is 9572849.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 13556129878225 + 78083308098576 = 3681865^2 + 8836476^2 .

It is not a de Polignac number, because 91639437976801 - 2¹¹ = 91639437974753 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91639437926801) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 1368883936 + ... + 1368950878.

Almost surely, 2^{91639437976801} is an apocalyptic number.

91639437976801 is the 9572849-th square number.

91639437976801 is the 4786425-th centered octagonal number.

It is an amenable number.

91639437976801 is a deficient number, since it is larger than the sum of its proper divisors (17434140168626).

91639437976801 is an frugal number, since it uses more digits than its factorization.

91639437976801 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133934 (or 66967 counting only the distinct ones).

The product of its (nonzero) digits is 370355328, while the sum is 73.

The spelling of 91639437976801 in words is "ninety-one trillion, six hundred thirty-nine billion, four hundred thirty-seven million, nine hundred seventy-six thousand, eight hundred one".