91987588 has 72 divisors (see below), whose sum is σ = 213012800. Its totient is φ = 33929280.

The previous prime is 91987547. The next prime is 91987589. The reversal of 91987588 is 88578919.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91987589) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 63658 + ... + 65086.

Almost surely, 2^91987588 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 91987588, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (106506400).

91987588 is an abundant number, since it is smaller than the sum of its proper divisors (121025212).

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

91987588 is a wasteful number, since it uses less digits than its factorization.

91987588 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1481 (or 1468 counting only the distinct ones).

The product of its digits is 1451520, while the sum is 55.

The square root of 91987588 is about 9591.0160045743. The cubic root of 91987588 is about 451.4154411110.

The spelling of 91987588 in words is "ninety-one million, nine hundred eighty-seven thousand, five hundred eighty-eight".