21533152 has 48 divisors (see below), whose sum is σ = 46865952. Its totient is φ = 9687040.

The previous prime is 21533143. The next prime is 21533177. The reversal of 21533152 is 25133512.

It is a congruent number.

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, 11652 + ... + 13372.

It is an arithmetic number, because the mean of its divisors is an integer number (976374).

Almost surely, 2^21533152 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 21533152, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23432976).

21533152 is an abundant number, since it is smaller than the sum of its proper divisors (25332800).

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

21533152 is a wasteful number, since it uses less digits than its factorization.

21533152 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1771 (or 1763 counting only the distinct ones).

The product of its digits is 900, while the sum is 22.

The square root of 21533152 is about 4640.3827428349. The cubic root of 21533152 is about 278.2077359712.

Adding to 21533152 its reverse (25133512), we get a palindrome (46666664).

The spelling of 21533152 in words is "twenty-one million, five hundred thirty-three thousand, one hundred fifty-two".