20001121011121 has 2 divisors, whose sum is σ = 20001121011122. Its totient is φ = 20001121011120.

The previous prime is 20001121011097. The next prime is 20001121011133. The reversal of 20001121011121 is 12111012110002.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19966026608896 + 35094402225 = 4468336^2 + 187335^2 .

It is a cyclic number.

It is not a de Polignac number, because 20001121011121 - 2³⁹ = 19451365197233 is a prime.

It is not a weakly prime, because it can be changed into another prime (20001121011821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10000560505560 + 10000560505561.

It is an arithmetic number, because the mean of its divisors is an integer number (10000560505561).

Almost surely, 2^{20001121011121} is an apocalyptic number.

It is an amenable number.

20001121011121 is a deficient number, since it is larger than the sum of its proper divisors (1).

20001121011121 is an equidigital number, since it uses as much as digits as its factorization.

20001121011121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 20001121011121 its reverse (12111012110002), we get a palindrome (32112133121123).

The spelling of 20001121011121 in words is "twenty trillion, one billion, one hundred twenty-one million, eleven thousand, one hundred twenty-one".