1221021212112 has 200 divisors, whose sum is σ = 3937072256040. Its totient is φ = 362743557120.

The previous prime is 1221021212069. The next prime is 1221021212123. The reversal of 1221021212112 is 2112121201221.

It can be written as a sum of positive squares in 4 ways, for example, as 56642096016 + 1164379116096 = 237996^2 + 1079064^2 .

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

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 39 ways as a sum of consecutive naturals, for example, 760939 + ... + 1738122.

Almost surely, 2^{1221021212112} is an apocalyptic number.

1221021212112 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1221021212112 is an abundant number, since it is smaller than the sum of its proper divisors (2716051043928).

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

1221021212112 is a wasteful number, since it uses less digits than its factorization.

1221021212112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2499123 (or 2499108 counting only the distinct ones).

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

Adding to 1221021212112 its reverse (2112121201221), we get a palindrome (3333142413333).

The spelling of 1221021212112 in words is "one trillion, two hundred twenty-one billion, twenty-one million, two hundred twelve thousand, one hundred twelve".