21989044 has 96 divisors (see below), whose sum is σ = 51609600. Its totient is φ = 8114400.

The previous prime is 21989029. The next prime is 21989053. The reversal of 21989044 is 44098912.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21988994 and 21989012.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 467829 + ... + 467875.

It is an arithmetic number, because the mean of its divisors is an integer number (537600).

Almost surely, 2^21989044 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 21989044, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25804800).

21989044 is an abundant number, since it is smaller than the sum of its proper divisors (29620556).

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

21989044 is a wasteful number, since it uses less digits than its factorization.

21989044 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 114 (or 98 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 37.

The square root of 21989044 is about 4689.2477008578. The cubic root of 21989044 is about 280.1574114892.

The spelling of 21989044 in words is "twenty-one million, nine hundred eighty-nine thousand, forty-four".