1221200212212 has 36 divisors (see below), whose sum is σ = 3114240669540. Its totient is φ = 403464375552.

The previous prime is 1221200212181. The next prime is 1221200212237. The reversal of 1221200212212 is 2122120021221.

It is a happy number.

1221200212212 is a `hidden beast` number, since 1 + 221 + 20 + 0 + 212 + 212 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 55655415396 + 1165544796816 = 235914^2 + 1079604^2 .

It is a tau number, because it is divible by the number of its divisors (36).

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 (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 150094287 + ... + 150102422.

It is an arithmetic number, because the mean of its divisors is an integer number (86506685265).

Almost surely, 2^{1221200212212} is an apocalyptic number.

1221200212212 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1221200212212 is an abundant number, since it is smaller than the sum of its proper divisors (1893040457328).

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

1221200212212 is a wasteful number, since it uses less digits than its factorization.

1221200212212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 300196832 (or 300196827 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 1221200212212 its reverse (2122120021221), we get a palindrome (3343320233433).

It can be divided in two parts, 122120021221 and 2, that multiplied together give a palindrome (244240042442).

The spelling of 1221200212212 in words is "one trillion, two hundred twenty-one billion, two hundred million, two hundred twelve thousand, two hundred twelve".