21285952 has 56 divisors (see below), whose sum is σ = 44302680. Its totient is φ = 10137600.

The previous prime is 21285941. The next prime is 21285977. The reversal of 21285952 is 25958212.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 9834496 + 11451456 = 3136^2 + 3384^2 .

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, 210702 + ... + 210802.

Almost surely, 2^21285952 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21285952, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22151340).

21285952 is an abundant number, since it is smaller than the sum of its proper divisors (23016728).

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

21285952 is a wasteful number, since it uses less digits than its factorization.

21285952 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 239 (or 229 counting only the distinct ones).

The product of its digits is 14400, while the sum is 34.

The square root of 21285952 is about 4613.6701225814. The cubic root of 21285952 is about 277.1390301563.

The spelling of 21285952 in words is "twenty-one million, two hundred eighty-five thousand, nine hundred fifty-two".