2001220110121 has 4 divisors (see below), whose sum is σ = 2001277074132. Its totient is φ = 2001163146112.

The previous prime is 2001220110101. The next prime is 2001220110139. The reversal of 2001220110121 is 1210110221002.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 210612155625 + 1790607954496 = 458925^2 + 1338136^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2001220110121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2001220110101) 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 3 ways as a sum of consecutive naturals, for example, 28429276 + ... + 28499581.

It is an arithmetic number, because the mean of its divisors is an integer number (500319268533).

Almost surely, 2^{2001220110121} is an apocalyptic number.

It is an amenable number.

2001220110121 is a deficient number, since it is larger than the sum of its proper divisors (56964011).

2001220110121 is an equidigital number, since it uses as much as digits as its factorization.

2001220110121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56964010.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 2001220110121 its reverse (1210110221002), we get a palindrome (3211330331123).

The spelling of 2001220110121 in words is "two trillion, one billion, two hundred twenty million, one hundred ten thousand, one hundred twenty-one".