21969304 has 64 divisors (see below), whose sum is σ = 51010560. Its totient is φ = 8655360.

The previous prime is 21969293. The next prime is 21969313. The reversal of 21969304 is 40396912.

It is a Harshad number since it is a multiple of its sum of digits (34).

It is a self number, because there is not a number n which added to its sum of digits gives 21969304.

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 15 ways as a sum of consecutive naturals, for example, 44499 + ... + 44989.

It is an arithmetic number, because the mean of its divisors is an integer number (797040).

Almost surely, 2^21969304 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 21969304, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25505280).

21969304 is an abundant number, since it is smaller than the sum of its proper divisors (29041256).

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

21969304 is a wasteful number, since it uses less digits than its factorization.

21969304 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 568 (or 564 counting only the distinct ones).

The product of its (nonzero) digits is 11664, while the sum is 34.

The square root of 21969304 is about 4687.1424130274. The cubic root of 21969304 is about 280.0735521058.

The spelling of 21969304 in words is "twenty-one million, nine hundred sixty-nine thousand, three hundred four".