91645131 has 4 divisors (see below), whose sum is σ = 122193512. Its totient is φ = 61096752.

The previous prime is 91645117. The next prime is 91645157. The reversal of 91645131 is 13154619.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13154619 = 3 ⋅4384873.

It is a de Polignac number, because none of the positive numbers 2^k-91645131 is a prime.

It is a super-2 number, since 2×91645131² = 16797660072014322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91645171) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15274186 + ... + 15274191.

It is an arithmetic number, because the mean of its divisors is an integer number (30548378).

Almost surely, 2^91645131 is an apocalyptic number.

91645131 is a deficient number, since it is larger than the sum of its proper divisors (30548381).

91645131 is a wasteful number, since it uses less digits than its factorization.

91645131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30548380.

The product of its digits is 3240, while the sum is 30.

The square root of 91645131 is about 9573.1463479882. The cubic root of 91645131 is about 450.8545588647.

The spelling of 91645131 in words is "ninety-one million, six hundred forty-five thousand, one hundred thirty-one".