91181 has 4 divisors (see below), whose sum is σ = 96000. Its totient is φ = 86364.

The previous prime is 91163. The next prime is 91183. The reversal of 91181 is 18119.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 91181 - 2¹⁴ = 74797 is a prime.

It is a super-2 number, since 2×91181² = 16627949522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 91181.

It is not an unprimeable number, because it can be changed into a prime (91183) 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, 2381 + ... + 2418.

It is an arithmetic number, because the mean of its divisors is an integer number (24000).

2⁹¹¹⁸¹ is an apocalyptic number.

It is an amenable number.

91181 is a deficient number, since it is larger than the sum of its proper divisors (4819).

91181 is a wasteful number, since it uses less digits than its factorization.

91181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4818.

The product of its digits is 72, while the sum is 20.

The square root of 91181 is about 301.9619181288. The cubic root of 91181 is about 45.0092162193.

It can be divided in two parts, 9118 and 1, that added together give a palindrome (9119).

The spelling of 91181 in words is "ninety-one thousand, one hundred eighty-one".