21544142 has 16 divisors (see below), whose sum is σ = 33143040. Its totient is φ = 10498488.

The previous prime is 21544139. The next prime is 21544181. The reversal of 21544142 is 24144512.

It is a plaindrome in base 16.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39113 + ... + 39659.

It is an arithmetic number, because the mean of its divisors is an integer number (2071440).

Almost surely, 2^21544142 is an apocalyptic number.

21544142 is a deficient number, since it is larger than the sum of its proper divisors (11598898).

21544142 is a wasteful number, since it uses less digits than its factorization.

21544142 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1015.

The product of its digits is 1280, while the sum is 23.

The square root of 21544142 is about 4641.5667613426. The cubic root of 21544142 is about 278.2550580881.

Adding to 21544142 its reverse (24144512), we get a palindrome (45688654).

The spelling of 21544142 in words is "twenty-one million, five hundred forty-four thousand, one hundred forty-two".