91081131 has 16 divisors (see below), whose sum is σ = 128421888. Its totient is φ = 57326400.

The previous prime is 91081099. The next prime is 91081147. The reversal of 91081131 is 13118019.

It is not a de Polignac number, because 91081131 - 2⁵ = 91081099 is a prime.

It is a super-2 number, since 2×91081131² = 16591544848478322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (91081031) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8131 + ... + 15756.

It is an arithmetic number, because the mean of its divisors is an integer number (8026368).

Almost surely, 2^91081131 is an apocalyptic number.

91081131 is a deficient number, since it is larger than the sum of its proper divisors (37340757).

91081131 is a wasteful number, since it uses less digits than its factorization.

91081131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23962.

The product of its (nonzero) digits is 216, while the sum is 24.

The square root of 91081131 is about 9543.6434866355. The cubic root of 91081131 is about 449.9277760632.

The spelling of 91081131 in words is "ninety-one million, eighty-one thousand, one hundred thirty-one".