21120212011109 has 2 divisors, whose sum is σ = 21120212011110. Its totient is φ = 21120212011108.

The previous prime is 21120212011027. The next prime is 21120212011133. The reversal of 21120212011109 is 90111021202112.

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., 20999507880484 + 120704130625 = 4582522^2 + 347425^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21120212011109 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21120212011139) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10560106005554 + 10560106005555.

It is an arithmetic number, because the mean of its divisors is an integer number (10560106005555).

Almost surely, 2^{21120212011109} is an apocalyptic number.

It is an amenable number.

21120212011109 is a deficient number, since it is larger than the sum of its proper divisors (1).

21120212011109 is an equidigital number, since it uses as much as digits as its factorization.

21120212011109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 144, while the sum is 23.

The spelling of 21120212011109 in words is "twenty-one trillion, one hundred twenty billion, two hundred twelve million, eleven thousand, one hundred nine".