18018990 has 64 divisors (see below), whose sum is σ = 52427520. Its totient is φ = 4367520.

The previous prime is 18018983. The next prime is 18018991. The reversal of 18018990 is 9981081.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18018991) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 64 + ... + 6003.

It is an arithmetic number, because the mean of its divisors is an integer number (819180).

Almost surely, 2^18018990 is an apocalyptic number.

18018990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 18018990, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26213760).

18018990 is an abundant number, since it is smaller than the sum of its proper divisors (34408530).

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

18018990 is a wasteful number, since it uses less digits than its factorization.

18018990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6094 (or 6088 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 36.

The square root of 18018990 is about 4244.8780901223. The cubic root of 18018990 is about 262.1662697683.

The spelling of 18018990 in words is "eighteen million, eighteen thousand, nine hundred ninety".