21271232 has 28 divisors (see below), whose sum is σ = 43013376. Its totient is φ = 10433280.

The previous prime is 21271231. The next prime is 21271247. The reversal of 21271232 is 23217212.

It is not an unprimeable number, because it can be changed into a prime (21271231) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 257 + ... + 6527.

It is an arithmetic number, because the mean of its divisors is an integer number (1536192).

Almost surely, 2^21271232 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 21271232, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21506688).

21271232 is an abundant number, since it is smaller than the sum of its proper divisors (21742144).

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

21271232 is an equidigital number, since it uses as much as digits as its factorization.

21271232 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6336 (or 6326 counting only the distinct ones).

The product of its digits is 336, while the sum is 20.

The square root of 21271232 is about 4612.0745874281. The cubic root of 21271232 is about 277.0751315617.

Adding to 21271232 its reverse (23217212), we get a palindrome (44488444).

The spelling of 21271232 in words is "twenty-one million, two hundred seventy-one thousand, two hundred thirty-two".