1221131113312 has 144 divisors (see below), whose sum is σ = 2724669009216. Its totient is φ = 538003065600.

The previous prime is 1221131113289. The next prime is 1221131113351. The reversal of 1221131113312 is 2133111311221.

It is a super-2 number, since 2×1221131113312² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 21782983 + ... + 21838969.

It is an arithmetic number, because the mean of its divisors is an integer number (18921312564).

Almost surely, 2^{1221131113312} 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 1221131113312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1362334504608).

1221131113312 is an abundant number, since it is smaller than the sum of its proper divisors (1503537895904).

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

1221131113312 is a wasteful number, since it uses less digits than its factorization.

1221131113312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56193 (or 56174 counting only the distinct ones).

The product of its digits is 216, while the sum is 22.

Adding to 1221131113312 its reverse (2133111311221), we get a palindrome (3354242424533).

The spelling of 1221131113312 in words is "one trillion, two hundred twenty-one billion, one hundred thirty-one million, one hundred thirteen thousand, three hundred twelve".