20121021200121 has 16 divisors (see below), whose sum is σ = 27206320927680. Its totient is φ = 13225721738240.

The previous prime is 20121021200113. The next prime is 20121021200167. The reversal of 20121021200121 is 12100212012102.

It is a cyclic number.

It is not a de Polignac number, because 20121021200121 - 2³ = 20121021200113 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 20121021200121.

It is not an unprimeable number, because it can be changed into a prime (20121021200321) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 106647435 + ... + 106835936.

It is an arithmetic number, because the mean of its divisors is an integer number (1700395057980).

Almost surely, 2^{20121021200121} is an apocalyptic number.

It is an amenable number.

20121021200121 is a deficient number, since it is larger than the sum of its proper divisors (7085299727559).

20121021200121 is a wasteful number, since it uses less digits than its factorization.

20121021200121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 213483816.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 20121021200121 its reverse (12100212012102), we get a palindrome (32221233212223).

The spelling of 20121021200121 in words is "twenty trillion, one hundred twenty-one billion, twenty-one million, two hundred thousand, one hundred twenty-one".