91689 has 8 divisors (see below), whose sum is σ = 131712. Its totient is φ = 56400.

The previous prime is 91673. The next prime is 91691. The reversal of 91689 is 98619.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 91689 - 2⁴ = 91673 is a prime.

It is not an unprimeable number, because it can be changed into a prime (91639) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1137 + ... + 1214.

It is an arithmetic number, because the mean of its divisors is an integer number (16464).

2⁹¹⁶⁸⁹ is an apocalyptic number.

It is an amenable number.

91689 is a deficient number, since it is larger than the sum of its proper divisors (40023).

91689 is a wasteful number, since it uses less digits than its factorization.

91689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2367.

The product of its digits is 3888, while the sum is 33.

The square root of 91689 is about 302.8019154497. The cubic root of 91689 is about 45.0926486249.

It can be divided in two parts, 91 and 689, that added together give a triangular number (780 = T₃₉).

The spelling of 91689 in words is "ninety-one thousand, six hundred eighty-nine".