22404144 has 80 divisors (see below), whose sum is σ = 66781440. Its totient is φ = 6339840.

The previous prime is 22404143. The next prime is 22404149. The reversal of 22404144 is 44140422.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a self number, because there is not a number n which added to its sum of digits gives 22404144.

It is not an unprimeable number, because it can be changed into a prime (22404143) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 43762 + ... + 44270.

It is an arithmetic number, because the mean of its divisors is an integer number (834768).

Almost surely, 2^22404144 is an apocalyptic number.

22404144 is a gapful number since it is divisible by the number (24) 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 22404144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33390720).

22404144 is an abundant number, since it is smaller than the sum of its proper divisors (44377296).

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

22404144 is a wasteful number, since it uses less digits than its factorization.

22404144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 658 (or 652 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 21.

The square root of 22404144 is about 4733.3015961377. The cubic root of 22404144 is about 281.9093315476.

Adding to 22404144 its reverse (44140422), we get a palindrome (66544566).

The spelling of 22404144 in words is "twenty-two million, four hundred four thousand, one hundred forty-four".