21552543 has 12 divisors (see below), whose sum is σ = 31526560. Its totient is φ = 14186016.

The previous prime is 21552529. The next prime is 21552551. The reversal of 21552543 is 34525512.

It is a happy number.

It is not a de Polignac number, because 21552543 - 2⁹ = 21552031 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21552563) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 14446 + ... + 15867.

Almost surely, 2^21552543 is an apocalyptic number.

21552543 is a deficient number, since it is larger than the sum of its proper divisors (9974017).

21552543 is a wasteful number, since it uses less digits than its factorization.

21552543 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30398 (or 30395 counting only the distinct ones).

The product of its digits is 6000, while the sum is 27.

The square root of 21552543 is about 4642.4716477325. The cubic root of 21552543 is about 278.2912213131.

The spelling of 21552543 in words is "twenty-one million, five hundred fifty-two thousand, five hundred forty-three".