91173 has 4 divisors (see below), whose sum is σ = 121568. Its totient is φ = 60780.

The previous prime is 91163. The next prime is 91183. The reversal of 91173 is 37119.

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: 37119 = 3 ⋅12373.

It is an interprime number because it is at equal distance from previous prime (91163) and next prime (91183).

It is not a de Polignac number, because 91173 - 2⁵ = 91141 is a prime.

It is a D-number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91153) 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, 15193 + ... + 15198.

It is an arithmetic number, because the mean of its divisors is an integer number (30392).

2⁹¹¹⁷³ is an apocalyptic number.

It is an amenable number.

91173 is a deficient number, since it is larger than the sum of its proper divisors (30395).

91173 is a wasteful number, since it uses less digits than its factorization.

91173 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30394.

The product of its digits is 189, while the sum is 21.

The square root of 91173 is about 301.9486711347. The cubic root of 91173 is about 45.0078998477.

The spelling of 91173 in words is "ninety-one thousand, one hundred seventy-three".