21904272 has 60 divisors (see below), whose sum is σ = 66022684. Its totient is φ = 6739200.

The previous prime is 21904271. The next prime is 21904273. The reversal of 21904272 is 27240912.

It is an interprime number because it is at equal distance from previous prime (21904271) and next prime (21904273).

It can be written as a sum of positive squares in 2 ways, for example, as 9960336 + 11943936 = 3156^2 + 3456^2 .

It is not an unprimeable number, because it can be changed into a prime (21904271) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3979 + ... + 7722.

Almost surely, 2^21904272 is an apocalyptic number.

It is an amenable number.

21904272 is an abundant number, since it is smaller than the sum of its proper divisors (44118412).

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

21904272 is a wasteful number, since it uses less digits than its factorization.

21904272 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11728 (or 11719 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The square root of 21904272 is about 4680.1999957267. The cubic root of 21904272 is about 279.7969275855.

The spelling of 21904272 in words is "twenty-one million, nine hundred four thousand, two hundred seventy-two".