1221201221012 has 24 divisors (see below), whose sum is σ = 2141954442600. Its totient is φ = 609215523840.

The previous prime is 1221201221011. The next prime is 1221201221027. The reversal of 1221201221012 is 2101221021221.

It can be written as a sum of positive squares in 4 ways, for example, as 32412241156 + 1188788979856 = 180034^2 + 1090316^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221201221011) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 3663212 + ... + 3982652.

It is an arithmetic number, because the mean of its divisors is an integer number (89248101775).

Almost surely, 2^{1221201221012} is an apocalyptic number.

It is an amenable number.

1221201221012 is a deficient number, since it is larger than the sum of its proper divisors (920753221588).

1221201221012 is a wasteful number, since it uses less digits than its factorization.

1221201221012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 321611 (or 321609 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 1221201221012 its reverse (2101221021221), we get a palindrome (3322422242233).

The spelling of 1221201221012 in words is "one trillion, two hundred twenty-one billion, two hundred one million, two hundred twenty-one thousand, twelve".