1211221220112 has 30 divisors (see below), whose sum is σ = 3389737165022. Its totient is φ = 403740406656.

The previous prime is 1211221220107. The next prime is 1211221220129. The reversal of 1211221220112 is 2110221221121.

1211221220112 is a `hidden beast` number, since 1 + 211 + 221 + 220 + 1 + 12 = 666.

It can be written as a sum of positive squares in only one way, i.e., 1183126096656 + 28095123456 = 1087716^2 + 167616^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4205629093 + ... + 4205629380.

Almost surely, 2^{1211221220112} is an apocalyptic number.

1211221220112 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1211221220112 is an abundant number, since it is smaller than the sum of its proper divisors (2178515944910).

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

1211221220112 is a wasteful number, since it uses less digits than its factorization.

1211221220112 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8411258487 (or 8411258478 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 1211221220112 its reverse (2110221221121), we get a palindrome (3321442441233).

The spelling of 1211221220112 in words is "one trillion, two hundred eleven billion, two hundred twenty-one million, two hundred twenty thousand, one hundred twelve".