91861584 has 80 divisors (see below), whose sum is σ = 244032000. Its totient is φ = 29766528.

The previous prime is 91861577. The next prime is 91861673. The reversal of 91861584 is 48516819.

It is a super-2 number, since 2×91861584² = 16877101229978112, which contains 22 as substring.

Its product of digits (69120) is a multiple of the sum of its prime factors (432).

It is a congruent number.

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 15 ways as a sum of consecutive naturals, for example, 461517 + ... + 461715.

It is an arithmetic number, because the mean of its divisors is an integer number (3050400).

Almost surely, 2^91861584 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 91861584, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (122016000).

91861584 is an abundant number, since it is smaller than the sum of its proper divisors (152170416).

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

91861584 is a wasteful number, since it uses less digits than its factorization.

91861584 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 432 (or 426 counting only the distinct ones).

The product of its digits is 69120, while the sum is 42.

The square root of 91861584 is about 9584.4448978540. Note that the first 3 decimals coincide. The cubic root of 91861584 is about 451.2092316154.

The spelling of 91861584 in words is "ninety-one million, eight hundred sixty-one thousand, five hundred eighty-four".