21002344 has 64 divisors (see below), whose sum is σ = 46267200. Its totient is φ = 8832000.

The previous prime is 21002341. The next prime is 21002357. The reversal of 21002344 is 44320012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21002341) 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, 151027 + ... + 151165.

It is an arithmetic number, because the mean of its divisors is an integer number (722925).

Almost surely, 2^21002344 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 21002344, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23133600).

21002344 is an abundant number, since it is smaller than the sum of its proper divisors (25264856).

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

21002344 is a wasteful number, since it uses less digits than its factorization.

21002344 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 274 (or 270 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 16.

The square root of 21002344 is about 4582.8314391869. The cubic root of 21002344 is about 275.9026822058.

Adding to 21002344 its reverse (44320012), we get a palindrome (65322356).

It can be divided in two parts, 2100 and 2344, that added together give a palindrome (4444).

The spelling of 21002344 in words is "twenty-one million, two thousand, three hundred forty-four".