2121220121121 has 6 divisors (see below), whose sum is σ = 3063984619410.
Its totient is φ = 1414146747408.
The previous prime is 2121220121071. The next prime is 2121220121159. The reversal of 2121220121121 is 1211210221212.
2121220121121 is a `hidden beast` number, since 21 + 212 + 201 + 211 + 21 = 666.
It can be written as a sum of positive squares in only one way, i.e., 2116911511521 + 4308609600 = 1454961^2 + 65640^2
It is not a de Polignac number, because 2121220121121 - 218 = 2121219858977 is a prime.
It is a junction number, because it is equal to n+sod(n) for n = 2121220121094 and 2121220121103.
It is not an unprimeable number, because it can be changed into a prime (2121220121161) 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 5 ways as a sum of consecutive naturals, for example, 117845562276 + ... + 117845562293.
It is an arithmetic number, because the mean of its divisors is an integer number (510664103235).
Almost surely, 22121220121121 is an apocalyptic number.
It is an amenable number.
2121220121121 is a deficient number, since it is larger than the sum of its proper divisors (942764498289).
2121220121121 is a wasteful number, since it uses less digits than its factorization.
2121220121121 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 235691124575 (or 235691124572 counting only the distinct ones).
The product of its (nonzero) digits is 64, while the sum is 18.
Adding to 2121220121121 its reverse (1211210221212), we get a palindrome (3332430342333).
The spelling of 2121220121121 in words is "two trillion, one hundred twenty-one billion, two hundred twenty million, one hundred twenty-one thousand, one hundred twenty-one".