99181891 has 12 divisors (see below), whose sum is σ = 103190040. Its totient is φ = 95300960.

The previous prime is 99181889. The next prime is 99181903. The reversal of 99181891 is 19818199.

It is not a de Polignac number, because 99181891 - 2¹ = 99181889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (99181811) 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, 129951 + ... + 130711.

It is an arithmetic number, because the mean of its divisors is an integer number (8599170).

Almost surely, 2^99181891 is an apocalyptic number.

99181891 is a deficient number, since it is larger than the sum of its proper divisors (4008149).

99181891 is an equidigital number, since it uses as much as digits as its factorization.

99181891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 914 (or 867 counting only the distinct ones).

The product of its digits is 46656, while the sum is 46.

The square root of 99181891 is about 9959.0105432217. The cubic root of 99181891 is about 462.8896405799.

The spelling of 99181891 in words is "ninety-nine million, one hundred eighty-one thousand, eight hundred ninety-one".