91281 has 4 divisors (see below), whose sum is σ = 121712. Its totient is φ = 60852.

The previous prime is 91253. The next prime is 91283. The reversal of 91281 is 18219.

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, and also an emirpimes, since its reverse is a distinct semiprime: 18219 = 3 ⋅6073.

It is not a de Polignac number, because 91281 - 2⁵ = 91249 is a prime.

It is a super-2 number, since 2×91281² = 16664441922, which contains 22 as substring.

It is a D-number.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 91281.

It is not an unprimeable number, because it can be changed into a prime (91283) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15211 + ... + 15216.

It is an arithmetic number, because the mean of its divisors is an integer number (30428).

2⁹¹²⁸¹ is an apocalyptic number.

It is an amenable number.

91281 is a deficient number, since it is larger than the sum of its proper divisors (30431).

91281 is a wasteful number, since it uses less digits than its factorization.

91281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30430.

The product of its digits is 144, while the sum is 21.

The square root of 91281 is about 302.1274565477. The cubic root of 91281 is about 45.0256643727.

The spelling of 91281 in words is "ninety-one thousand, two hundred eighty-one".