22428 has 36 divisors (see below), whose sum is σ = 65520. Its totient is φ = 6336.

The previous prime is 22409. The next prime is 22433. The reversal of 22428 is 82422.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a plaindrome in base 16.

It is a self number, because there is not a number n which added to its sum of digits gives 22428.

It is a congruent number.

It is an unprimeable number.

22428 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 208 + ... + 296.

It is an arithmetic number, because the mean of its divisors is an integer number (1820).

2²²⁴²⁸ is an apocalyptic number.

22428 is a gapful number since it is divisible by the number (28) 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 22428, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32760).

22428 is an abundant number, since it is smaller than the sum of its proper divisors (43092).

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

22428 is a wasteful number, since it uses less digits than its factorization.

22428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106 (or 101 counting only the distinct ones).

The product of its digits is 256, while the sum is 18.

The square root of 22428 is about 149.7598076922. The cubic root of 22428 is about 28.2009355356.

It can be divided in two parts, 224 and 28, that added together give a palindrome (252).

The spelling of 22428 in words is "twenty-two thousand, four hundred twenty-eight".