21612448 has 48 divisors (see below), whose sum is σ = 49998816. Its totient is φ = 9066240.

The previous prime is 21612431. The next prime is 21612497. The reversal of 21612448 is 84421612.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2215 + ... + 6937.

It is an arithmetic number, because the mean of its divisors is an integer number (1041642).

Almost surely, 2^21612448 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 21612448, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24999408).

21612448 is an abundant number, since it is smaller than the sum of its proper divisors (28386368).

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

21612448 is a wasteful number, since it uses less digits than its factorization.

21612448 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4757 (or 4749 counting only the distinct ones).

The product of its digits is 3072, while the sum is 28.

The square root of 21612448 is about 4648.9190141365. The cubic root of 21612448 is about 278.5488183521.

The spelling of 21612448 in words is "twenty-one million, six hundred twelve thousand, four hundred forty-eight".