13221221312 has 56 divisors (see below), whose sum is σ = 28518252336. Its totient is φ = 6045032448.

The previous prime is 13221221267. The next prime is 13221221327. The reversal of 13221221312 is 21312212231.

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, 14768 + ... + 163280.

It is an arithmetic number, because the mean of its divisors is an integer number (509254506).

Almost surely, 2^13221221312 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 13221221312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (14259126168).

13221221312 is an abundant number, since it is smaller than the sum of its proper divisors (15297031024).

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

13221221312 is a wasteful number, since it uses less digits than its factorization.

13221221312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 148645 (or 148635 counting only the distinct ones).

The product of its digits is 288, while the sum is 20.

Adding to 13221221312 its reverse (21312212231), we get a palindrome (34533433543).

The spelling of 13221221312 in words is "thirteen billion, two hundred twenty-one million, two hundred twenty-one thousand, three hundred twelve".