21942444 has 48 divisors (see below), whose sum is σ = 56095200. Its totient is φ = 6644736.

The previous prime is 21942379. The next prime is 21942457. The reversal of 21942444 is 44424912.

It is a nialpdrome in base 12.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4062 + ... + 7770.

It is an arithmetic number, because the mean of its divisors is an integer number (1168650).

Almost surely, 2^21942444 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 21942444, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28047600).

21942444 is an abundant number, since it is smaller than the sum of its proper divisors (34152756).

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

21942444 is a wasteful number, since it uses less digits than its factorization.

21942444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3762 (or 3760 counting only the distinct ones).

The product of its digits is 9216, while the sum is 30.

The square root of 21942444 is about 4684.2762514608. The cubic root of 21942444 is about 279.9593648514.

The spelling of 21942444 in words is "twenty-one million, nine hundred forty-two thousand, four hundred forty-four".