21929344 has 64 divisors (see below), whose sum is σ = 47001600. Its totient is φ = 10160640.

The previous prime is 21929339. The next prime is 21929357. The reversal of 21929344 is 44392912.

It is a tau number, because it is divible by the number of its divisors (64).

It is a super-2 number, since 2×21929344² = 961792256540672, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 172609 + ... + 172735.

It is an arithmetic number, because the mean of its divisors is an integer number (734400).

Almost surely, 2^21929344 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 21929344, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23500800).

21929344 is an abundant number, since it is smaller than the sum of its proper divisors (25072256).

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

21929344 is a wasteful number, since it uses less digits than its factorization.

21929344 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 231 (or 219 counting only the distinct ones).

The product of its digits is 15552, while the sum is 34.

The square root of 21929344 is about 4682.8777477103. The cubic root of 21929344 is about 279.9036403118.

The spelling of 21929344 in words is "twenty-one million, nine hundred twenty-nine thousand, three hundred forty-four".