18361590 has 96 divisors (see below), whose sum is σ = 50168160. Its totient is φ = 4274688.

The previous prime is 18361589. The next prime is 18361601. The reversal of 18361590 is 9516381.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 206266 + ... + 206354.

It is an arithmetic number, because the mean of its divisors is an integer number (522585).

Almost surely, 2^18361590 is an apocalyptic number.

18361590 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 18361590, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25084080).

18361590 is an abundant number, since it is smaller than the sum of its proper divisors (31806570).

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

18361590 is a wasteful number, since it uses less digits than its factorization.

18361590 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 158 (or 135 counting only the distinct ones).

The product of its (nonzero) digits is 6480, while the sum is 33.

The square root of 18361590 is about 4285.0425902201. The cubic root of 18361590 is about 263.8173955336.

The spelling of 18361590 in words is "eighteen million, three hundred sixty-one thousand, five hundred ninety".