18284220 has 72 divisors (see below), whose sum is σ = 55901664. Its totient is φ = 4837248.

The previous prime is 18284219. The next prime is 18284257. The reversal of 18284220 is 2248281.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 27937 + ... + 28583.

It is an arithmetic number, because the mean of its divisors is an integer number (776412).

Almost surely, 2^18284220 is an apocalyptic number.

18284220 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 18284220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27950832).

18284220 is an abundant number, since it is smaller than the sum of its proper divisors (37617444).

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

18284220 is a wasteful number, since it uses less digits than its factorization.

18284220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 819 (or 814 counting only the distinct ones).

The product of its (nonzero) digits is 2048, while the sum is 27.

The square root of 18284220 is about 4276.0051449922. The cubic root of 18284220 is about 263.4463258442.

The spelling of 18284220 in words is "eighteen million, two hundred eighty-four thousand, two hundred twenty".