21344232 has 128 divisors (see below), whose sum is σ = 68140800. Its totient is φ = 5419008.

The previous prime is 21344209. The next prime is 21344237. The reversal of 21344232 is 23244312.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 21344199 and 21344208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21344237) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 63168 + ... + 63504.

It is an arithmetic number, because the mean of its divisors is an integer number (532350).

Almost surely, 2^21344232 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 21344232, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34070400).

21344232 is an abundant number, since it is smaller than the sum of its proper divisors (46796568).

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

21344232 is a wasteful number, since it uses less digits than its factorization.

21344232 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 395 (or 391 counting only the distinct ones).

The product of its digits is 1152, while the sum is 21.

The square root of 21344232 is about 4619.9818181460. The cubic root of 21344232 is about 277.3917311586.

Adding to 21344232 its reverse (23244312), we get a palindrome (44588544).

The spelling of 21344232 in words is "twenty-one million, three hundred forty-four thousand, two hundred thirty-two".