18998005 has 16 divisors (see below), whose sum is σ = 25845120. Its totient is φ = 13290048.

The previous prime is 18997997. The next prime is 18998033. The reversal of 18998005 is 50089981.

It is a cyclic number.

It is not a de Polignac number, because 18998005 - 2³ = 18997997 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6457 + ... + 8926.

It is an arithmetic number, because the mean of its divisors is an integer number (1615320).

Almost surely, 2^18998005 is an apocalyptic number.

It is an amenable number.

18998005 is a deficient number, since it is larger than the sum of its proper divisors (6847115).

18998005 is a wasteful number, since it uses less digits than its factorization.

18998005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15420.

The product of its (nonzero) digits is 25920, while the sum is 40.

The square root of 18998005 is about 4358.6700953387. The cubic root of 18998005 is about 266.8308251395.

The spelling of 18998005 in words is "eighteen million, nine hundred ninety-eight thousand, five".