21445056 has 84 divisors (see below), whose sum is σ = 63504064. Its totient is φ = 6912000.

The previous prime is 21445037. The next prime is 21445111. The reversal of 21445056 is 65054412.

It is a congruent number.

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 11 ways as a sum of consecutive naturals, for example, 17256 + ... + 18456.

Almost surely, 2^21445056 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 21445056, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31752032).

21445056 is an abundant number, since it is smaller than the sum of its proper divisors (42059008).

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

21445056 is a wasteful number, since it uses less digits than its factorization.

21445056 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1250 (or 1237 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 27.

The square root of 21445056 is about 4630.8806937774. The cubic root of 21445056 is about 277.8278180901.

Adding to 21445056 its reverse (65054412), we get a palindrome (86499468).

The spelling of 21445056 in words is "twenty-one million, four hundred forty-five thousand, fifty-six".