1221221212112 has 80 divisors (see below), whose sum is σ = 2603987238912. Its totient is φ = 550212082560.

The previous prime is 1221221212069. The next prime is 1221221212153. The reversal of 1221221212112 is 2112121221221.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24271493 + ... + 24321755.

Almost surely, 2^{1221221212112} 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 1221221212112, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1301993619456).

1221221212112 is an abundant number, since it is smaller than the sum of its proper divisors (1382766026800).

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

1221221212112 is a wasteful number, since it uses less digits than its factorization.

1221221212112 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51496 (or 51490 counting only the distinct ones).

The product of its digits is 128, while the sum is 20.

Adding to 1221221212112 its reverse (2112121221221), we get a palindrome (3333342433333).

The spelling of 1221221212112 in words is "one trillion, two hundred twenty-one billion, two hundred twenty-one million, two hundred twelve thousand, one hundred twelve".