91988685 has 24 divisors (see below), whose sum is σ = 159849144. Its totient is φ = 48936960.

The previous prime is 91988681. The next prime is 91988711. The reversal of 91988685 is 58688919.

It can be written as a sum of positive squares in 4 ways, for example, as 1320201 + 90668484 = 1149^2 + 9522^2 .

It is not a de Polignac number, because 91988685 - 2² = 91988681 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91988681) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 17125 + ... + 21845.

It is an arithmetic number, because the mean of its divisors is an integer number (6660381).

Almost surely, 2^91988685 is an apocalyptic number.

It is an amenable number.

91988685 is a deficient number, since it is larger than the sum of its proper divisors (67860459).

91988685 is a wasteful number, since it uses less digits than its factorization.

91988685 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5165 (or 5162 counting only the distinct ones).

The product of its digits is 1244160, while the sum is 54.

The square root of 91988685 is about 9591.0731933397. The cubic root of 91988685 is about 451.4172355588.

The spelling of 91988685 in words is "ninety-one million, nine hundred eighty-eight thousand, six hundred eighty-five".