21544768 has 28 divisors (see below), whose sum is σ = 48861472. Its totient is φ = 9233280.

The previous prime is 21544759. The next prime is 21544799. The reversal of 21544768 is 86744512.

It is a tau number, because it is divible by the number of its divisors (28).

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 3 ways as a sum of consecutive naturals, for example, 23598 + ... + 24493.

Almost surely, 2^21544768 is an apocalyptic number.

21544768 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21544768 is an abundant number, since it is smaller than the sum of its proper divisors (27316704).

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

21544768 is an equidigital number, since it uses as much as digits as its factorization.

21544768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48110 (or 48100 counting only the distinct ones).

The product of its digits is 53760, while the sum is 37.

The square root of 21544768 is about 4641.6341949792. The cubic root of 21544768 is about 278.2577531127.

The spelling of 21544768 in words is "twenty-one million, five hundred forty-four thousand, seven hundred sixty-eight".