18189906 has 16 divisors (see below), whose sum is σ = 41577024. Its totient is φ = 5197104.

The previous prime is 18189889. The next prime is 18189917. The reversal of 18189906 is 60998181.

It is a Harshad number since it is a multiple of its sum of digits (42), and also a Moran number because the ratio is a prime number: 433093 = 18189906 / (1 + 8 + 1 + 8 + 9 + 9 + 0 + 6).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 216505 + ... + 216588.

It is an arithmetic number, because the mean of its divisors is an integer number (2598564).

Almost surely, 2^18189906 is an apocalyptic number.

18189906 is an abundant number, since it is smaller than the sum of its proper divisors (23387118).

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

18189906 is a wasteful number, since it uses less digits than its factorization.

18189906 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 433105.

The product of its (nonzero) digits is 31104, while the sum is 42.

The square root of 18189906 is about 4264.9626024152. The cubic root of 18189906 is about 262.9925735348.

The spelling of 18189906 in words is "eighteen million, one hundred eighty-nine thousand, nine hundred six".