18221814 has 64 divisors (see below), whose sum is σ = 44210880. Its totient is φ = 5529600.

The previous prime is 18221783. The next prime is 18221821. The reversal of 18221814 is 41812281.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 70774 + ... + 71030.

It is an arithmetic number, because the mean of its divisors is an integer number (690795).

Almost surely, 2^18221814 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18221814, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22105440).

18221814 is an abundant number, since it is smaller than the sum of its proper divisors (25989066).

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

18221814 is a wasteful number, since it uses less digits than its factorization.

18221814 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 382 (or 376 counting only the distinct ones).

The product of its digits is 1024, while the sum is 27.

The square root of 18221814 is about 4268.7016761540. The cubic root of 18221814 is about 263.1462606969.

The spelling of 18221814 in words is "eighteen million, two hundred twenty-one thousand, eight hundred fourteen".