22644 has 36 divisors (see below), whose sum is σ = 62244. Its totient is φ = 6912.

The previous prime is 22643. The next prime is 22651. The reversal of 22644 is 44622.

22644 is a `hidden beast` number, since 22 + 644 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 19044 + 3600 = 138^2 + 60^2 .

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 nude number because it is divisible by every one of its digits.

Its product of digits (384) is a multiple of the sum of its prime factors (64).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 594 + ... + 630.

It is an arithmetic number, because the mean of its divisors is an integer number (1729).

2²²⁶⁴⁴ 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 22644, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31122).

22644 is an abundant number, since it is smaller than the sum of its proper divisors (39600).

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

22644 is a wasteful number, since it uses less digits than its factorization.

22644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64 (or 59 counting only the distinct ones).

The product of its digits is 384, while the sum is 18.

The square root of 22644 is about 150.4792344478. The cubic root of 22644 is about 28.2911791444.

It can be divided in two parts, 22 and 644, that added together give a palindrome (666).

The spelling of 22644 in words is "twenty-two thousand, six hundred forty-four".