21224328 has 32 divisors (see below), whose sum is σ = 53222400. Its totient is φ = 7053248.

The previous prime is 21224323. The next prime is 21224351. The reversal of 21224328 is 82342212.

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

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 21224298 and 21224307.

It is not an unprimeable number, because it can be changed into a prime (21224321) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8038 + ... + 10346.

It is an arithmetic number, because the mean of its divisors is an integer number (1663200).

Almost surely, 2^21224328 is an apocalyptic number.

It is an amenable number.

21224328 is an abundant number, since it is smaller than the sum of its proper divisors (31998072).

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

21224328 is a wasteful number, since it uses less digits than its factorization.

21224328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2701 (or 2697 counting only the distinct ones).

The product of its digits is 1536, while the sum is 24.

The square root of 21224328 is about 4606.9868677911. The cubic root of 21224328 is about 276.8713274145.

The spelling of 21224328 in words is "twenty-one million, two hundred twenty-four thousand, three hundred twenty-eight".