91605 has 16 divisors (see below), whose sum is σ = 152064. Its totient is φ = 47040.

The previous prime is 91591. The next prime is 91621. The reversal of 91605 is 50619.

It is not a de Polignac number, because 91605 - 2⁵ = 91573 is a prime.

91605 is a lucky number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 367 + ... + 563.

It is an arithmetic number, because the mean of its divisors is an integer number (9504).

2⁹¹⁶⁰⁵ is an apocalyptic number.

It is an amenable number.

91605 is a deficient number, since it is larger than the sum of its proper divisors (60459).

91605 is a wasteful number, since it uses less digits than its factorization.

91605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 236.

The product of its (nonzero) digits is 270, while the sum is 21.

The square root of 91605 is about 302.6631791282. The cubic root of 91605 is about 45.0788740180.

It can be divided in two parts, 91 and 605, that multiplied together give a palindrome (55055).

The spelling of 91605 in words is "ninety-one thousand, six hundred five".