18331620 has 48 divisors (see below), whose sum is σ = 51817920. Its totient is φ = 4841856.

The previous prime is 18331609. The next prime is 18331639. The reversal of 18331620 is 2613381.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5139 + ... + 7941.

It is an arithmetic number, because the mean of its divisors is an integer number (1079540).

Almost surely, 2^18331620 is an apocalyptic number.

18331620 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18331620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25908960).

18331620 is an abundant number, since it is smaller than the sum of its proper divisors (33486300).

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

18331620 is a wasteful number, since it uses less digits than its factorization.

18331620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2924 (or 2922 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 24.

The square root of 18331620 is about 4281.5441139850. The cubic root of 18331620 is about 263.6737820992.

The spelling of 18331620 in words is "eighteen million, three hundred thirty-one thousand, six hundred twenty".