21725392 has 40 divisors (see below), whose sum is σ = 45700200. Its totient is φ = 9945600.

The previous prime is 21725383. The next prime is 21725411. The reversal of 21725392 is 29352712.

It can be written as a sum of positive squares in 4 ways, for example, as 712336 + 21013056 = 844^2 + 4584^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 30642 + ... + 31342.

It is an arithmetic number, because the mean of its divisors is an integer number (1142505).

Almost surely, 2^21725392 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 21725392, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22850100).

21725392 is an abundant number, since it is smaller than the sum of its proper divisors (23974808).

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

21725392 is a wasteful number, since it uses less digits than its factorization.

21725392 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 871 (or 865 counting only the distinct ones).

The product of its digits is 7560, while the sum is 31.

The square root of 21725392 is about 4661.0505253644. The cubic root of 21725392 is about 279.0331962059.

The spelling of 21725392 in words is "twenty-one million, seven hundred twenty-five thousand, three hundred ninety-two".