21253241344 has 40 divisors (see below), whose sum is σ = 42642895680. Its totient is φ = 10582096896.

The previous prime is 21253241341. The next prime is 21253241351. The reversal of 21253241344 is 44314235212.

It is not an unprimeable number, because it can be changed into a prime (21253241341) 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, 35527 + ... + 209209.

It is an arithmetic number, because the mean of its divisors is an integer number (1066072392).

Almost surely, 2^21253241344 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 21253241344, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21321447840).

21253241344 is an abundant number, since it is smaller than the sum of its proper divisors (21389654336).

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

21253241344 is an equidigital number, since it uses as much as digits as its factorization.

21253241344 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 173940 (or 173924 counting only the distinct ones).

The product of its digits is 23040, while the sum is 31.

Adding to 21253241344 its reverse (44314235212), we get a palindrome (65567476556).

The spelling of 21253241344 in words is "twenty-one billion, two hundred fifty-three million, two hundred forty-one thousand, three hundred forty-four".