21512752 has 40 divisors (see below), whose sum is σ = 44528400. Its totient is φ = 10033152.

The previous prime is 21512749. The next prime is 21512759. The reversal of 21512752 is 25721512.

It is a super-2 number, since 2×21512752² = 925596997227008, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21512759) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 37524 + ... + 38092.

It is an arithmetic number, because the mean of its divisors is an integer number (1113210).

Almost surely, 2^21512752 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 21512752, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22264200).

21512752 is an abundant number, since it is smaller than the sum of its proper divisors (23015648).

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

21512752 is a wasteful number, since it uses less digits than its factorization.

21512752 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 733 (or 727 counting only the distinct ones).

The product of its digits is 1400, while the sum is 25.

The square root of 21512752 is about 4638.1841274361. The cubic root of 21512752 is about 278.1198523981.

The spelling of 21512752 in words is "twenty-one million, five hundred twelve thousand, seven hundred fifty-two".