21544252 has 24 divisors (see below), whose sum is σ = 40288640. Its totient is φ = 10050480.

The previous prime is 21544231. The next prime is 21544273. The reversal of 21544252 is 25244512.

It is an interprime number because it is at equal distance from previous prime (21544231) and next prime (21544273).

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, 2977 + ... + 7207.

Almost surely, 2^21544252 is an apocalyptic number.

It is an amenable number.

21544252 is a deficient number, since it is larger than the sum of its proper divisors (18744388).

21544252 is a wasteful number, since it uses less digits than its factorization.

21544252 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4321 (or 4319 counting only the distinct ones).

The product of its digits is 3200, while the sum is 25.

The square root of 21544252 is about 4641.5786107746. The cubic root of 21544252 is about 278.2555316585.

Adding to 21544252 its reverse (25244512), we get a palindrome (46788764).

The spelling of 21544252 in words is "twenty-one million, five hundred forty-four thousand, two hundred fifty-two".