21037272 has 48 divisors (see below), whose sum is σ = 55012440. Its totient is φ = 6703488.

The previous prime is 21037271. The next prime is 21037283. The reversal of 21037272 is 27273012.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21037271) 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 11 ways as a sum of consecutive naturals, for example, 11868 + ... + 13524.

Almost surely, 2^21037272 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 21037272, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27506220).

21037272 is an abundant number, since it is smaller than the sum of its proper divisors (33975168).

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

21037272 is a wasteful number, since it uses less digits than its factorization.

21037272 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1712 (or 1685 counting only the distinct ones).

The product of its (nonzero) digits is 1176, while the sum is 24.

The square root of 21037272 is about 4586.6406007011. The cubic root of 21037272 is about 276.0555443766.

The spelling of 21037272 in words is "twenty-one million, thirty-seven thousand, two hundred seventy-two".