21544422 has 16 divisors (see below), whose sum is σ = 44962560. Its totient is φ = 6869192.

The previous prime is 21544421. The next prime is 21544427. The reversal of 21544422 is 22444512.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21544392 and 21544401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21544421) 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, 77922 + ... + 78197.

It is an arithmetic number, because the mean of its divisors is an integer number (2810160).

Almost surely, 2^21544422 is an apocalyptic number.

21544422 is an abundant number, since it is smaller than the sum of its proper divisors (23418138).

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

21544422 is a wasteful number, since it uses less digits than its factorization.

21544422 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 156147.

The product of its digits is 2560, while the sum is 24.

The square root of 21544422 is about 4641.5969234736. The cubic root of 21544422 is about 278.2562635369.

Adding to 21544422 its reverse (22444512), we get a palindrome (43988934).

The spelling of 21544422 in words is "twenty-one million, five hundred forty-four thousand, four hundred twenty-two".