91917216 has 72 divisors (see below), whose sum is σ = 262997280. Its totient is φ = 30450816.

The previous prime is 91917209. The next prime is 91917227. The reversal of 91917216 is 61271919.

It is a tau number, because it is divible by the number of its divisors (72).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 50661 + ... + 52443.

It is an arithmetic number, because the mean of its divisors is an integer number (3652740).

Almost surely, 2^91917216 is an apocalyptic number.

91917216 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 91917216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (131498640).

91917216 is an abundant number, since it is smaller than the sum of its proper divisors (171080064).

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

91917216 is a wasteful number, since it uses less digits than its factorization.

91917216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1978 (or 1967 counting only the distinct ones).

The product of its digits is 6804, while the sum is 36.

The square root of 91917216 is about 9587.3466610945. The cubic root of 91917216 is about 451.3002983607.

The spelling of 91917216 in words is "ninety-one million, nine hundred seventeen thousand, two hundred sixteen".