21255532 has 6 divisors (see below), whose sum is σ = 37197188. Its totient is φ = 10627764.

The previous prime is 21255529. The next prime is 21255541. The reversal of 21255532 is 23555212.

It is a happy number.

It is a plaindrome in base 16.

It is a junction number, because it is equal to n+sod(n) for n = 21255497 and 21255506.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2656938 + ... + 2656945.

Almost surely, 2^21255532 is an apocalyptic number.

It is an amenable number.

21255532 is a deficient number, since it is larger than the sum of its proper divisors (15941656).

21255532 is a wasteful number, since it uses less digits than its factorization.

21255532 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5313887 (or 5313885 counting only the distinct ones).

The product of its digits is 3000, while the sum is 25.

The square root of 21255532 is about 4610.3722192465. The cubic root of 21255532 is about 277.0069463519.

The spelling of 21255532 in words is "twenty-one million, two hundred fifty-five thousand, five hundred thirty-two".