18398224 has 40 divisors (see below), whose sum is σ = 38669400. Its totient is φ = 8429568.

The previous prime is 18398207. The next prime is 18398227. The reversal of 18398224 is 42289381.

It can be written as a sum of positive squares in 4 ways, for example, as 5438224 + 12960000 = 2332^2 + 3600^2 .

It is not an unprimeable number, because it can be changed into a prime (18398227) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 40752 + ... + 41200.

It is an arithmetic number, because the mean of its divisors is an integer number (966735).

Almost surely, 2^18398224 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 18398224, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19334700).

18398224 is an abundant number, since it is smaller than the sum of its proper divisors (20271176).

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

18398224 is a wasteful number, since it uses less digits than its factorization.

18398224 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 667 (or 661 counting only the distinct ones).

The product of its digits is 27648, while the sum is 37.

The square root of 18398224 is about 4289.3150968424. The cubic root of 18398224 is about 263.9927301334.

The spelling of 18398224 in words is "eighteen million, three hundred ninety-eight thousand, two hundred twenty-four".