21992272 has 40 divisors (see below), whose sum is σ = 45512960. Its totient is φ = 10264320.

The previous prime is 21992249. The next prime is 21992273. The reversal of 21992272 is 27229912.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21992273) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21697 + ... + 22687.

It is an arithmetic number, because the mean of its divisors is an integer number (1137824).

Almost surely, 2^21992272 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 21992272, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22756480).

21992272 is an abundant number, since it is smaller than the sum of its proper divisors (23520688).

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

21992272 is a wasteful number, since it uses less digits than its factorization.

21992272 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1091 (or 1085 counting only the distinct ones).

The product of its digits is 9072, while the sum is 34.

The square root of 21992272 is about 4689.5918798974. The cubic root of 21992272 is about 280.1711198899.

The spelling of 21992272 in words is "twenty-one million, nine hundred ninety-two thousand, two hundred seventy-two".