99891918 has 24 divisors (see below), whose sum is σ = 247351728. Its totient is φ = 28540512.

The previous prime is 99891917. The next prime is 99891919. The reversal of 99891918 is 81919899.

It is an interprime number because it is at equal distance from previous prime (99891917) and next prime (99891919).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99891917) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 396271 + ... + 396522.

It is an arithmetic number, because the mean of its divisors is an integer number (10306322).

Almost surely, 2^99891918 is an apocalyptic number.

99891918 is an abundant number, since it is smaller than the sum of its proper divisors (147459810).

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

99891918 is a wasteful number, since it uses less digits than its factorization.

99891918 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 792808 (or 792805 counting only the distinct ones).

The product of its digits is 419904, while the sum is 54.

The square root of 99891918 is about 9994.5944389955. The cubic root of 99891918 is about 463.9915990106.

The spelling of 99891918 in words is "ninety-nine million, eight hundred ninety-one thousand, nine hundred eighteen".