21052472 has 64 divisors (see below), whose sum is σ = 47523840. Its totient is φ = 8553600.

The previous prime is 21052469. The next prime is 21052481. The reversal of 21052472 is 27425012.

It is a happy number.

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, 116222 + ... + 116402.

It is an arithmetic number, because the mean of its divisors is an integer number (742560).

Almost surely, 2^21052472 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 21052472, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23761920).

21052472 is an abundant number, since it is smaller than the sum of its proper divisors (26471368).

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

21052472 is a wasteful number, since it uses less digits than its factorization.

21052472 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 292 (or 288 counting only the distinct ones).

The product of its (nonzero) digits is 1120, while the sum is 23.

The square root of 21052472 is about 4588.2972876657. The cubic root of 21052472 is about 276.1220142449.

Adding to 21052472 its reverse (27425012), we get a palindrome (48477484).

The spelling of 21052472 in words is "twenty-one million, fifty-two thousand, four hundred seventy-two".