20111121211009 has 2 divisors, whose sum is σ = 20111121211010. Its totient is φ = 20111121211008.

The previous prime is 20111121211007. The next prime is 20111121211021. The reversal of 20111121211009 is 90011212111102.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15329989114609 + 4781132096400 = 3915353^2 + 2186580^2 .

It is a cyclic number.

It is not a de Polignac number, because 20111121211009 - 2¹ = 20111121211007 is a prime.

It is a super-2 number, since 2×20111121211009² (a number of 27 digits) contains 22 as substring.

Together with 20111121211007, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (20111121211007) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10055560605504 + 10055560605505.

It is an arithmetic number, because the mean of its divisors is an integer number (10055560605505).

Almost surely, 2^{20111121211009} is an apocalyptic number.

It is an amenable number.

20111121211009 is a deficient number, since it is larger than the sum of its proper divisors (1).

20111121211009 is an equidigital number, since it uses as much as digits as its factorization.

20111121211009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72, while the sum is 22.

The spelling of 20111121211009 in words is "twenty trillion, one hundred eleven billion, one hundred twenty-one million, two hundred eleven thousand, nine".