21385952 has 72 divisors (see below), whose sum is σ = 51193296. Its totient is φ = 8752128.

The previous prime is 21385951. The next prime is 21385961. The reversal of 21385952 is 25958312.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21385951) 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, 35768 + ... + 36360.

It is an arithmetic number, because the mean of its divisors is an integer number (711018).

Almost surely, 2^21385952 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 21385952, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25596648).

21385952 is an abundant number, since it is smaller than the sum of its proper divisors (29807344).

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

21385952 is a wasteful number, since it uses less digits than its factorization.

21385952 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 640 (or 625 counting only the distinct ones).

The product of its digits is 21600, while the sum is 35.

The square root of 21385952 is about 4624.4947832169. The cubic root of 21385952 is about 277.5723459346.

The spelling of 21385952 in words is "twenty-one million, three hundred eighty-five thousand, nine hundred fifty-two".