22638440 has 64 divisors (see below), whose sum is σ = 58008960. Its totient is φ = 7870720.

The previous prime is 22638397. The next prime is 22638457. The reversal of 22638440 is 4483622.

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, 9002 + ... + 11238.

It is an arithmetic number, because the mean of its divisors is an integer number (906390).

Almost surely, 2^22638440 is an apocalyptic number.

22638440 is a gapful number since it is divisible by the number (20) 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 22638440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29004480).

22638440 is an abundant number, since it is smaller than the sum of its proper divisors (35370520).

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

22638440 is a wasteful number, since it uses less digits than its factorization.

22638440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2282 (or 2278 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 29.

The square root of 22638440 is about 4757.9869692970. The cubic root of 22638440 is about 282.8886341936. Note that the first 3 decimals are identical.

The spelling of 22638440 in words is "twenty-two million, six hundred thirty-eight thousand, four hundred forty".