21545344 has 16 divisors (see below), whose sum is σ = 42922620. Its totient is φ = 10772608.

The previous prime is 21545339. The next prime is 21545351. The reversal of 21545344 is 44354512.

It is a tau number, because it is divible by the number of its divisors (16).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 84034 + ... + 84289.

Almost surely, 2^21545344 is an apocalyptic number.

It is an amenable number.

21545344 is a deficient number, since it is larger than the sum of its proper divisors (21377276).

21545344 is an equidigital number, since it uses as much as digits as its factorization.

21545344 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 168337 (or 168325 counting only the distinct ones).

The product of its digits is 9600, while the sum is 28.

The square root of 21545344 is about 4641.6962416772. The cubic root of 21545344 is about 278.2602328337.

Adding to 21545344 its reverse (44354512), we get a palindrome (65899856).

The spelling of 21545344 in words is "twenty-one million, five hundred forty-five thousand, three hundred forty-four".