91765 has 4 divisors (see below), whose sum is σ = 110124. Its totient is φ = 73408.

The previous prime is 91757. The next prime is 91771. The reversal of 91765 is 56719.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 56719 = 13 ⋅4363.

It can be written as a sum of positive squares in 2 ways, for example, as 13924 + 77841 = 118^2 + 279^2 .

It is a cyclic number.

It is not a de Polignac number, because 91765 - 2³ = 91757 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9172 + ... + 9181.

It is an arithmetic number, because the mean of its divisors is an integer number (27531).

2⁹¹⁷⁶⁵ is an apocalyptic number.

It is an amenable number.

91765 is a deficient number, since it is larger than the sum of its proper divisors (18359).

91765 is a wasteful number, since it uses less digits than its factorization.

91765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18358.

The product of its digits is 1890, while the sum is 28.

The square root of 91765 is about 302.9273840378. The cubic root of 91765 is about 45.1051041170.

The spelling of 91765 in words is "ninety-one thousand, seven hundred sixty-five".