1221000221112 has 256 divisors, whose sum is σ = 3629262412800. Its totient is φ = 335045652480.

The previous prime is 1221000221107. The next prime is 1221000221141. The reversal of 1221000221112 is 2111220001221.

It is a junction number, because it is equal to n+sod(n) for n = 1221000221091 and 1221000221100.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 405511687 + ... + 405514697.

It is an arithmetic number, because the mean of its divisors is an integer number (14176806300).

Almost surely, 2^{1221000221112} is an apocalyptic number.

1221000221112 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1221000221112, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1814631206400).

1221000221112 is an abundant number, since it is smaller than the sum of its proper divisors (2408262191688).

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

1221000221112 is a wasteful number, since it uses less digits than its factorization.

1221000221112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3886 (or 3882 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 1221000221112 its reverse (2111220001221), we get a palindrome (3332220222333).

The spelling of 1221000221112 in words is "one trillion, two hundred twenty-one billion, two hundred twenty-one thousand, one hundred twelve".