20111121211021 has 2 divisors, whose sum is σ = 20111121211022. Its totient is φ = 20111121211020.

The previous prime is 20111121211009. The next prime is 20111121211031. The reversal of 20111121211021 is 12011212111102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18842423097796 + 1268698113225 = 4340786^2 + 1126365^2 .

It is a cyclic number.

It is not a de Polignac number, because 20111121211021 - 2¹³ = 20111121202829 is a prime.

It is a super-2 number, since 2×20111121211021² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20111121210986 and 20111121211004.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20111121211031) 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, 10055560605510 + 10055560605511.

It is an arithmetic number, because the mean of its divisors is an integer number (10055560605511).

Almost surely, 2^{20111121211021} is an apocalyptic number.

It is an amenable number.

20111121211021 is a deficient number, since it is larger than the sum of its proper divisors (1).

20111121211021 is an equidigital number, since it uses as much as digits as its factorization.

20111121211021 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 20111121211021 its reverse (12011212111102), we get a palindrome (32122333322123).

The spelling of 20111121211021 in words is "twenty trillion, one hundred eleven billion, one hundred twenty-one million, two hundred eleven thousand, twenty-one".