21452556 has 24 divisors (see below), whose sum is σ = 50425200. Its totient is φ = 7098112.

The previous prime is 21452549. The next prime is 21452567. The reversal of 21452556 is 65525412.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4881 + ... + 8168.

It is an arithmetic number, because the mean of its divisors is an integer number (2101050).

Almost surely, 2^21452556 is an apocalyptic number.

It is an amenable number.

21452556 is an abundant number, since it is smaller than the sum of its proper divisors (28972644).

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

21452556 is a wasteful number, since it uses less digits than its factorization.

21452556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13193 (or 13191 counting only the distinct ones).

The product of its digits is 12000, while the sum is 30.

The square root of 21452556 is about 4631.6904041613. The cubic root of 21452556 is about 277.8602026449.

Adding to 21452556 its reverse (65525412), we get a palindrome (86977968).

The spelling of 21452556 in words is "twenty-one million, four hundred fifty-two thousand, five hundred fifty-six".