21903732 has 72 divisors (see below), whose sum is σ = 60220160. Its totient is φ = 6687360.

The previous prime is 21903719. The next prime is 21903733. The reversal of 21903732 is 23730912.

It is a junction number, because it is equal to n+sod(n) for n = 21903696 and 21903705.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21903733) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 20688 + ... + 21720.

Almost surely, 2^21903732 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 21903732, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30110080).

21903732 is an abundant number, since it is smaller than the sum of its proper divisors (38316428).

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

21903732 is a wasteful number, since it uses less digits than its factorization.

21903732 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1093 (or 1088 counting only the distinct ones).

The product of its (nonzero) digits is 2268, while the sum is 27.

The square root of 21903732 is about 4680.1423055288. The cubic root of 21903732 is about 279.7946283144.

The spelling of 21903732 in words is "twenty-one million, nine hundred three thousand, seven hundred thirty-two".