20111011212121 has 2 divisors, whose sum is σ = 20111011212122. Its totient is φ = 20111011212120.

The previous prime is 20111011212101. The next prime is 20111011212139. The reversal of 20111011212121 is 12121211011102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12594975123600 + 7516036088521 = 3548940^2 + 2741539^2 .

It is a cyclic number.

It is not a de Polignac number, because 20111011212121 - 2²¹ = 20111009114969 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20111011212095 and 20111011212104.

It is not a weakly prime, because it can be changed into another prime (20111011212101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10055505606060 + 10055505606061.

It is an arithmetic number, because the mean of its divisors is an integer number (10055505606061).

Almost surely, 2^{20111011212121} is an apocalyptic number.

It is an amenable number.

20111011212121 is a deficient number, since it is larger than the sum of its proper divisors (1).

20111011212121 is an equidigital number, since it uses as much as digits as its factorization.

20111011212121 is an odious number, because the sum of its binary digits is odd.

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

Adding to 20111011212121 its reverse (12121211011102), we get a palindrome (32232222223223).

The spelling of 20111011212121 in words is "twenty trillion, one hundred eleven billion, eleven million, two hundred twelve thousand, one hundred twenty-one".