21652224 has 108 divisors (see below), whose sum is σ = 63613368. Its totient is φ = 6533120.

The previous prime is 21652219. The next prime is 21652273. The reversal of 21652224 is 42225612.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a junction number, because it is equal to n+sod(n) for n = 21652194 and 21652203.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 92812 + ... + 93044.

Almost surely, 2^21652224 is an apocalyptic number.

21652224 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21652224, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31806684).

21652224 is an abundant number, since it is smaller than the sum of its proper divisors (41961144).

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

21652224 is a wasteful number, since it uses less digits than its factorization.

21652224 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 274 (or 249 counting only the distinct ones).

The product of its digits is 1920, while the sum is 24.

The square root of 21652224 is about 4653.1950313736. The cubic root of 21652224 is about 278.7195959787.

Adding to 21652224 its reverse (42225612), we get a palindrome (63877836).

The spelling of 21652224 in words is "twenty-one million, six hundred fifty-two thousand, two hundred twenty-four".