91986 has 8 divisors (see below), whose sum is σ = 183984. Its totient is φ = 30660.

The previous prime is 91969. The next prime is 91997. The reversal of 91986 is 68919.

It is a happy number.

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

91986 is an admirable number.

It is a super-2 number, since 2×91986² = 16922848392, which contains 22 as substring.

It is a Curzon 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, 7660 + ... + 7671.

It is an arithmetic number, because the mean of its divisors is an integer number (22998).

2⁹¹⁹⁸⁶ is an apocalyptic number.

91986 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (91992).

91986 is a wasteful number, since it uses less digits than its factorization.

91986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15336.

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

The square root of 91986 is about 303.2919385674. The cubic root of 91986 is about 45.1412843471.

The spelling of 91986 in words is "ninety-one thousand, nine hundred eighty-six".