221211112009 has 2 divisors, whose sum is σ = 221211112010. Its totient is φ = 221211112008.

The previous prime is 221211112007. The next prime is 221211112021. The reversal of 221211112009 is 900211112122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 122864270400 + 98346841609 = 350520^2 + 313603^2 .

It is a cyclic number.

It is not a de Polignac number, because 221211112009 - 2¹ = 221211112007 is a prime.

Together with 221211112007, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (221211112007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110605556004 + 110605556005.

It is an arithmetic number, because the mean of its divisors is an integer number (110605556005).

Almost surely, 2^221211112009 is an apocalyptic number.

It is an amenable number.

221211112009 is a deficient number, since it is larger than the sum of its proper divisors (1).

221211112009 is an equidigital number, since it uses as much as digits as its factorization.

221211112009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 144, while the sum is 22.

The spelling of 221211112009 in words is "two hundred twenty-one billion, two hundred eleven million, one hundred twelve thousand, nine".