91686816 has 144 divisors (see below), whose sum is σ = 291511584. Its totient is φ = 28180224.

The previous prime is 91686811. The next prime is 91686823. The reversal of 91686816 is 61868619.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (144).

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (91686811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 100635 + ... + 101541.

It is an arithmetic number, because the mean of its divisors is an integer number (2024386).

Almost surely, 2^91686816 is an apocalyptic number.

91686816 is a gapful number since it is divisible by the number (96) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 91686816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (145755792).

91686816 is an abundant number, since it is smaller than the sum of its proper divisors (199824768).

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

91686816 is a wasteful number, since it uses less digits than its factorization.

91686816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 945 (or 925 counting only the distinct ones).

The product of its digits is 124416, while the sum is 45.

The square root of 91686816 is about 9575.3232843596. The cubic root of 91686816 is about 450.9229059164.

The spelling of 91686816 in words is "ninety-one million, six hundred eighty-six thousand, eight hundred sixteen".