21440132 has 48 divisors (see below), whose sum is σ = 45588480. Its totient is φ = 8618400.

The previous prime is 21440129. The next prime is 21440137. The reversal of 21440132 is 23104412.

It is a self number, because there is not a number n which added to its sum of digits gives 21440132.

It is not an unprimeable number, because it can be changed into a prime (21440137) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 101507 + ... + 101717.

It is an arithmetic number, because the mean of its divisors is an integer number (949760).

Almost surely, 2^21440132 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 21440132, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22794240).

21440132 is an abundant number, since it is smaller than the sum of its proper divisors (24148348).

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

21440132 is a wasteful number, since it uses less digits than its factorization.

21440132 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 432 (or 430 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 21440132 is about 4630.3490149232. The cubic root of 21440132 is about 277.8065524443.

Adding to 21440132 its reverse (23104412), we get a palindrome (44544544).

The spelling of 21440132 in words is "twenty-one million, four hundred forty thousand, one hundred thirty-two".