21224748 has 48 divisors (see below), whose sum is σ = 52613120. Its totient is φ = 6640704.

The previous prime is 21224741. The next prime is 21224759. The reversal of 21224748 is 84742212.

It is not an unprimeable number, because it can be changed into a prime (21224741) by changing a digit.

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, 28590 + ... + 29322.

Almost surely, 2^21224748 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 21224748, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26306560).

21224748 is an abundant number, since it is smaller than the sum of its proper divisors (31388372).

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

21224748 is a wasteful number, since it uses less digits than its factorization.

21224748 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 886 (or 884 counting only the distinct ones).

The product of its digits is 7168, while the sum is 30.

The square root of 21224748 is about 4607.0324505043. The cubic root of 21224748 is about 276.8731537023.

The spelling of 21224748 in words is "twenty-one million, two hundred twenty-four thousand, seven hundred forty-eight".