21120011012209 has 2 divisors, whose sum is σ = 21120011012210. Its totient is φ = 21120011012208.

The previous prime is 21120011012197. The next prime is 21120011012231. The reversal of 21120011012209 is 90221011002112.

It is an a-pointer prime, because the next prime (21120011012231) can be obtained adding 21120011012209 to its sum of digits (22).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15877156698225 + 5242854313984 = 3984615^2 + 2289728^2 .

It is a cyclic number.

It is not a de Polignac number, because 21120011012209 - 2⁷ = 21120011012081 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21120011012209.

It is not a weakly prime, because it can be changed into another prime (21120011015209) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10560005506104 + 10560005506105.

It is an arithmetic number, because the mean of its divisors is an integer number (10560005506105).

Almost surely, 2^{21120011012209} is an apocalyptic number.

It is an amenable number.

21120011012209 is a deficient number, since it is larger than the sum of its proper divisors (1).

21120011012209 is an equidigital number, since it uses as much as digits as its factorization.

21120011012209 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 22.

The spelling of 21120011012209 in words is "twenty-one trillion, one hundred twenty billion, eleven million, twelve thousand, two hundred nine".