21124152 has 80 divisors (see below), whose sum is σ = 67634160. Its totient is φ = 6034176.

The previous prime is 21124141. The next prime is 21124163. The reversal of 21124152 is 25142112.

It is an interprime number because it is at equal distance from previous prime (21124141) and next prime (21124163).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 2208 + ... + 6864.

It is an arithmetic number, because the mean of its divisors is an integer number (845427).

Almost surely, 2^21124152 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 21124152, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33817080).

21124152 is an abundant number, since it is smaller than the sum of its proper divisors (46510008).

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

21124152 is a wasteful number, since it uses less digits than its factorization.

21124152 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4682 (or 4669 counting only the distinct ones).

The product of its digits is 160, while the sum is 18.

The square root of 21124152 is about 4596.1018265482. The cubic root of 21124152 is about 276.4350416987.

Adding to 21124152 its reverse (25142112), we get a palindrome (46266264).

The spelling of 21124152 in words is "twenty-one million, one hundred twenty-four thousand, one hundred fifty-two".