91864224 has 72 divisors (see below), whose sum is σ = 262342080. Its totient is φ = 30492288.

The previous prime is 91864187. The next prime is 91864237. The reversal of 91864224 is 42246819.

91864224 is a `hidden beast` number, since 9 + 1 + 8 + 642 + 2 + 4 = 666.

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

It is a super-2 number, since 2×91864224² = 16878071302244352, which contains 22 as substring.

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

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

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 87897 + ... + 88935.

It is an arithmetic number, because the mean of its divisors is an integer number (3643640).

Almost surely, 2^91864224 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 91864224, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (131171040).

91864224 is an abundant number, since it is smaller than the sum of its proper divisors (170477856).

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

91864224 is a wasteful number, since it uses less digits than its factorization.

91864224 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1362 (or 1351 counting only the distinct ones).

The product of its digits is 27648, while the sum is 36.

The square root of 91864224 is about 9584.5826200206. The cubic root of 91864224 is about 451.2135539915.

The spelling of 91864224 in words is "ninety-one million, eight hundred sixty-four thousand, two hundred twenty-four".