21231121311344 has 160 divisors (see below), whose sum is σ = 50122141977600. Its totient is φ = 8515988084736.

The previous prime is 21231121311329. The next prime is 21231121311359. The reversal of 21231121311344 is 44311312113212.

It is an interprime number because it is at equal distance from previous prime (21231121311329) and next prime (21231121311359).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 25303412 + ... + 26129004.

It is an arithmetic number, because the mean of its divisors is an integer number (313263387360).

Almost surely, 2^{21231121311344} 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 21231121311344, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25061070988800).

21231121311344 is an abundant number, since it is smaller than the sum of its proper divisors (28891020666256).

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

21231121311344 is a wasteful number, since it uses less digits than its factorization.

21231121311344 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 825847 (or 825841 counting only the distinct ones).

The product of its digits is 3456, while the sum is 29.

Adding to 21231121311344 its reverse (44311312113212), we get a palindrome (65542433424556).

The spelling of 21231121311344 in words is "twenty-one trillion, two hundred thirty-one billion, one hundred twenty-one million, three hundred eleven thousand, three hundred forty-four".