91806 has 32 divisors (see below), whose sum is σ = 217728. Its totient is φ = 25440.

The previous prime is 91801. The next prime is 91807. The reversal of 91806 is 60819.

91806 is a nontrivial binomial coefficient, being equal to C(429, 2).

It is a plaindrome in base 16.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 91806.

It is not an unprimeable number, because it can be changed into a prime (91801) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 805 + ... + 911.

It is an arithmetic number, because the mean of its divisors is an integer number (6804).

2⁹¹⁸⁰⁶ is an apocalyptic number.

91806 is the 428-th triangular number.

It is a practical number, because each smaller number is the sum of distinct divisors of 91806, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (108864).

91806 is an abundant number, since it is smaller than the sum of its proper divisors (125922).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

91806 is a wasteful number, since it uses less digits than its factorization.

91806 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 136.

The product of its (nonzero) digits is 432, while the sum is 24.

The square root of 91806 is about 302.9950494645. The cubic root of 91806 is about 45.1118206717. Note that the first 3 decimals are identical.

The spelling of 91806 in words is "ninety-one thousand, eight hundred six".