20111121211 has 2 divisors, whose sum is σ = 20111121212. Its totient is φ = 20111121210.

The previous prime is 20111121209. The next prime is 20111121241. The reversal of 20111121211 is 11212111102.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20111121211 - 2¹ = 20111121209 is a prime.

Together with 20111121209, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 20111121191 and 20111121200.

It is not a weakly prime, because it can be changed into another prime (20111121241) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10055560605 + 10055560606.

It is an arithmetic number, because the mean of its divisors is an integer number (10055560606).

Almost surely, 2^20111121211 is an apocalyptic number.

20111121211 is a deficient number, since it is larger than the sum of its proper divisors (1).

20111121211 is an equidigital number, since it uses as much as digits as its factorization.

20111121211 is an evil number, because the sum of its binary digits is even.

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

Adding to 20111121211 its reverse (11212111102), we get a palindrome (31323232313).

The spelling of 20111121211 in words is "twenty billion, one hundred eleven million, one hundred twenty-one thousand, two hundred eleven".