2001211122121 has 2 divisors, whose sum is σ = 2001211122122. Its totient is φ = 2001211122120.

The previous prime is 2001211122041. The next prime is 2001211122193. The reversal of 2001211122121 is 1212211121002.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1782729665721 + 218481456400 = 1335189^2 + 467420^2 .

It is a cyclic number.

It is not a de Polignac number, because 2001211122121 - 2⁷ = 2001211121993 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2001211122095 and 2001211122104.

It is not a weakly prime, because it can be changed into another prime (2001211122821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1000605561060 + 1000605561061.

It is an arithmetic number, because the mean of its divisors is an integer number (1000605561061).

Almost surely, 2^{2001211122121} is an apocalyptic number.

It is an amenable number.

2001211122121 is a deficient number, since it is larger than the sum of its proper divisors (1).

2001211122121 is an equidigital number, since it uses as much as digits as its factorization.

2001211122121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 2001211122121 its reverse (1212211121002), we get a palindrome (3213422243123).

The spelling of 2001211122121 in words is "two trillion, one billion, two hundred eleven million, one hundred twenty-two thousand, one hundred twenty-one".