21442044 has 72 divisors (see below), whose sum is σ = 55236720. Its totient is φ = 6469632.

The previous prime is 21442037. The next prime is 21442063. The reversal of 21442044 is 44024412.

It is a super-2 number, since 2×21442044² = 919522501795872, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21442044.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 196662 + ... + 196770.

Almost surely, 2^21442044 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 21442044, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27618360).

21442044 is an abundant number, since it is smaller than the sum of its proper divisors (33794676).

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

21442044 is a wasteful number, since it uses less digits than its factorization.

21442044 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 239 (or 224 counting only the distinct ones).

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

The square root of 21442044 is about 4630.5554742385. Note that the first 3 decimals coincide. The cubic root of 21442044 is about 277.8148103279.

Adding to 21442044 its reverse (44024412), we get a palindrome (65466456).

The spelling of 21442044 in words is "twenty-one million, four hundred forty-two thousand, forty-four".