91331 has 2 divisors, whose sum is σ = 91332. Its totient is φ = 91330.

The previous prime is 91309. The next prime is 91367. The reversal of 91331 is 13319.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-91331 is a prime.

It is a super-2 number, since 2×91331² = 16682703122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (91381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45665 + 45666.

It is an arithmetic number, because the mean of its divisors is an integer number (45666).

2⁹¹³³¹ is an apocalyptic number.

91331 is a deficient number, since it is larger than the sum of its proper divisors (1).

91331 is an equidigital number, since it uses as much as digits as its factorization.

91331 is an evil number, because the sum of its binary digits is even.

The product of its digits is 81, while the sum is 17.

The square root of 91331 is about 302.2101917540. The cubic root of 91331 is about 45.0338839448.

The spelling of 91331 in words is "ninety-one thousand, three hundred thirty-one".