99981588 has 48 divisors (see below), whose sum is σ = 268567040. Its totient is φ = 28357344.

The previous prime is 99981571. The next prime is 99981593. The reversal of 99981588 is 88518999.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7395 + ... + 15957.

Almost surely, 2^99981588 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 99981588, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (134283520).

99981588 is an abundant number, since it is smaller than the sum of its proper divisors (168585452).

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

99981588 is a wasteful number, since it uses less digits than its factorization.

99981588 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8716 (or 8714 counting only the distinct ones).

The product of its digits is 1866240, while the sum is 57.

The square root of 99981588 is about 9999.0793576209. The cubic root of 99981588 is about 464.1303946349.

The spelling of 99981588 in words is "ninety-nine million, nine hundred eighty-one thousand, five hundred eighty-eight".