21372344 has 32 divisors (see below), whose sum is σ = 46387200. Its totient is φ = 9041760.

The previous prime is 21372343. The next prime is 21372353. The reversal of 21372344 is 44327312.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21372343) 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, 2009 + ... + 6839.

It is an arithmetic number, because the mean of its divisors is an integer number (1449600).

Almost surely, 2^21372344 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 21372344, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23193600).

21372344 is an abundant number, since it is smaller than the sum of its proper divisors (25014856).

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

21372344 is a wasteful number, since it uses less digits than its factorization.

21372344 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4923 (or 4919 counting only the distinct ones).

The product of its digits is 4032, while the sum is 26.

The square root of 21372344 is about 4623.0232532402. The cubic root of 21372344 is about 277.5134598346.

Adding to 21372344 its reverse (44327312), we get a palindrome (65699656).

The spelling of 21372344 in words is "twenty-one million, three hundred seventy-two thousand, three hundred forty-four".