20121221122013 has 6 divisors (see below), whose sum is σ = 22116714125982. Its totient is φ = 18292019201720.

The previous prime is 20121221121893. The next prime is 20121221122111. The reversal of 20121221122013 is 31022112212102.

It can be written as a sum of positive squares in only one way, i.e., 20076833795524 + 44387326489 = 4480718^2 + 210683^2 .

It is not a de Polignac number, because 20121221122013 - 2¹⁰ = 20121221120989 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20121221152013) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 83145541706 + ... + 83145541947.

It is an arithmetic number, because the mean of its divisors is an integer number (3686119020997).

Almost surely, 2^{20121221122013} is an apocalyptic number.

It is an amenable number.

20121221122013 is a deficient number, since it is larger than the sum of its proper divisors (1995493003969).

20121221122013 is a wasteful number, since it uses less digits than its factorization.

20121221122013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 166291083675 (or 166291083664 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 20.

Adding to 20121221122013 its reverse (31022112212102), we get a palindrome (51143333334115).

The spelling of 20121221122013 in words is "twenty trillion, one hundred twenty-one billion, two hundred twenty-one million, one hundred twenty-two thousand, thirteen".