91231 has 4 divisors (see below), whose sum is σ = 104272. Its totient is φ = 78192.

The previous prime is 91229. The next prime is 91237. The reversal of 91231 is 13219.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 91231 - 2¹ = 91229 is a prime.

It is a super-2 number, since 2×91231² = 16646190722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91237) 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, 6510 + ... + 6523.

It is an arithmetic number, because the mean of its divisors is an integer number (26068).

2⁹¹²³¹ is an apocalyptic number.

91231 is a deficient number, since it is larger than the sum of its proper divisors (13041).

91231 is a wasteful number, since it uses less digits than its factorization.

91231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13040.

The product of its digits is 54, while the sum is 16.

The square root of 91231 is about 302.0446986789. The cubic root of 91231 is about 45.0174417984.

The spelling of 91231 in words is "ninety-one thousand, two hundred thirty-one".