21556448 has 12 divisors (see below), whose sum is σ = 42439320. Its totient is φ = 10778208.

The previous prime is 21556441. The next prime is 21556477. The reversal of 21556448 is 84465512.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21556441) by changing a digit.

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 as a sum of consecutive naturals, namely, 336788 + ... + 336851.

It is an arithmetic number, because the mean of its divisors is an integer number (3536610).

Almost surely, 2^21556448 is an apocalyptic number.

It is an amenable number.

21556448 is a deficient number, since it is larger than the sum of its proper divisors (20882872).

21556448 is an equidigital number, since it uses as much as digits as its factorization.

21556448 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 673649 (or 673641 counting only the distinct ones).

The product of its digits is 38400, while the sum is 35.

The square root of 21556448 is about 4642.8922020654. The cubic root of 21556448 is about 278.3080277072.

The spelling of 21556448 in words is "twenty-one million, five hundred fifty-six thousand, four hundred forty-eight".