21229152 has 72 divisors (see below), whose sum is σ = 64839096. Its totient is φ = 6064128.

The previous prime is 21229147. The next prime is 21229163. The reversal of 21229152 is 25192212.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2448 + ... + 6960.

It is an arithmetic number, because the mean of its divisors is an integer number (900543).

Almost surely, 2^21229152 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 21229152, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32419548).

21229152 is an abundant number, since it is smaller than the sum of its proper divisors (43609944).

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

21229152 is a wasteful number, since it uses less digits than its factorization.

21229152 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4540 (or 4525 counting only the distinct ones).

The product of its digits is 720, while the sum is 24.

The square root of 21229152 is about 4607.5103906557. The cubic root of 21229152 is about 276.8923021831.

The spelling of 21229152 in words is "twenty-one million, two hundred twenty-nine thousand, one hundred fifty-two".