18885990 has 64 divisors (see below), whose sum is σ = 47941632. Its totient is φ = 4752000.

The previous prime is 18885983. The next prime is 18885991. The reversal of 18885990 is 9958881.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18885991) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 69555 + ... + 69825.

It is an arithmetic number, because the mean of its divisors is an integer number (749088).

Almost surely, 2^18885990 is an apocalyptic number.

18885990 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 18885990, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23970816).

18885990 is an abundant number, since it is smaller than the sum of its proper divisors (29055642).

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

18885990 is a wasteful number, since it uses less digits than its factorization.

18885990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 405.

The product of its (nonzero) digits is 207360, while the sum is 48.

The square root of 18885990 is about 4345.8014220624. The cubic root of 18885990 is about 266.3053666074.

The spelling of 18885990 in words is "eighteen million, eight hundred eighty-five thousand, nine hundred ninety".