18236224 has 28 divisors (see below), whose sum is σ = 36539424. Its totient is φ = 9029504.

The previous prime is 18236221. The next prime is 18236243. The reversal of 18236224 is 42263281.

It is a junction number, because it is equal to n+sod(n) for n = 18236192 and 18236201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18236221) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5517 + ... + 8179.

Almost surely, 2^18236224 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18236224, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18269712).

18236224 is an abundant number, since it is smaller than the sum of its proper divisors (18303200).

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

18236224 is a wasteful number, since it uses less digits than its factorization.

18236224 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2782 (or 2772 counting only the distinct ones).

The product of its digits is 4608, while the sum is 28.

The square root of 18236224 is about 4270.3892094281. The cubic root of 18236224 is about 263.2156086862.

The spelling of 18236224 in words is "eighteen million, two hundred thirty-six thousand, two hundred twenty-four".