21231423344 has 40 divisors (see below), whose sum is σ = 42632271360. Its totient is φ = 10232280000.

The previous prime is 21231423337. The next prime is 21231423359. The reversal of 21231423344 is 44332413212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39227 + ... + 209765.

It is an arithmetic number, because the mean of its divisors is an integer number (1065806784).

Almost surely, 2^21231423344 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 21231423344, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21316135680).

21231423344 is an abundant number, since it is smaller than the sum of its proper divisors (21400848016).

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

21231423344 is a wasteful number, since it uses less digits than its factorization.

21231423344 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 170829 (or 170823 counting only the distinct ones).

The product of its digits is 13824, while the sum is 29.

Adding to 21231423344 its reverse (44332413212), we get a palindrome (65563836556).

The spelling of 21231423344 in words is "twenty-one billion, two hundred thirty-one million, four hundred twenty-three thousand, three hundred forty-four".