201211122220121 has 16 divisors (see below), whose sum is σ = 217561340891664. Its totient is φ = 184985732481024.

The previous prime is 201211122220103. The next prime is 201211122220127. The reversal of 201211122220121 is 121022221112102.

It can be written as a sum of positive squares in 8 ways, for example, as 6872466728521 + 194338655491600 = 2621539^2 + 13940540^2 .

It is a cyclic number.

It is not a de Polignac number, because 201211122220121 - 2¹⁸ = 201211121957977 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 201211122220093 and 201211122220102.

It is not an unprimeable number, because it can be changed into a prime (201211122220127) 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, 20782475 + ... + 28884831.

It is an arithmetic number, because the mean of its divisors is an integer number (13597583805729).

Almost surely, 2^{201211122220121} is an apocalyptic number.

It is an amenable number.

201211122220121 is a deficient number, since it is larger than the sum of its proper divisors (16350218671543).

201211122220121 is a wasteful number, since it uses less digits than its factorization.

201211122220121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8110060.

The product of its (nonzero) digits is 128, while the sum is 20.

Adding to 201211122220121 its reverse (121022221112102), we get a palindrome (322233343332223).

The spelling of 201211122220121 in words is "two hundred one trillion, two hundred eleven billion, one hundred twenty-two million, two hundred twenty thousand, one hundred twenty-one".