21940032 has 56 divisors (see below), whose sum is σ = 58420000. Its totient is φ = 7266816.

The previous prime is 21940027. The next prime is 21940063. The reversal of 21940032 is 23004912.

21940032 is nontrivially palindromic in base 5.

It is a super-2 number, since 2×21940032² = 962730008322048, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21939990 and 21940008.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 43719 + ... + 44217.

Almost surely, 2^21940032 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 21940032, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29210000).

21940032 is an abundant number, since it is smaller than the sum of its proper divisors (36479968).

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

21940032 is a wasteful number, since it uses less digits than its factorization.

21940032 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 743 (or 733 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 21.

The square root of 21940032 is about 4684.0187873236. The cubic root of 21940032 is about 279.9491063963.

Adding to 21940032 its reverse (23004912), we get a palindrome (44944944).

The spelling of 21940032 in words is "twenty-one million, nine hundred forty thousand, thirty-two".