18989091 has 24 divisors (see below), whose sum is σ = 30438720. Its totient is φ = 11310000.

The previous prime is 18989071. The next prime is 18989141. The reversal of 18989091 is 19098981.

It is not a de Polignac number, because 18989091 - 2⁵ = 18989059 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18989041) 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, 4216 + ... + 7466.

It is an arithmetic number, because the mean of its divisors is an integer number (1268280).

Almost surely, 2^18989091 is an apocalyptic number.

18989091 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

18989091 is a deficient number, since it is larger than the sum of its proper divisors (11449629).

18989091 is a wasteful number, since it uses less digits than its factorization.

18989091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3327 (or 3324 counting only the distinct ones).

The product of its (nonzero) digits is 46656, while the sum is 45.

The square root of 18989091 is about 4357.6474157508. The cubic root of 18989091 is about 266.7890856327.

It can be divided in two parts, 189890 and 91, that added together give a palindrome (189981).

The spelling of 18989091 in words is "eighteen million, nine hundred eighty-nine thousand, ninety-one".