201210111122221 has 2 divisors, whose sum is σ = 201210111122222. Its totient is φ = 201210111122220.

The previous prime is 201210111122219. The next prime is 201210111122227. The reversal of 201210111122221 is 122221111012102.

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., 201200437416196 + 9673706025 = 14184514^2 + 98355^2 .

It is a cyclic number.

It is not a de Polignac number, because 201210111122221 - 2¹ = 201210111122219 is a prime.

Together with 201210111122219, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (201210111122227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100605055561110 + 100605055561111.

It is an arithmetic number, because the mean of its divisors is an integer number (100605055561111).

Almost surely, 2^{201210111122221} is an apocalyptic number.

It is an amenable number.

201210111122221 is a deficient number, since it is larger than the sum of its proper divisors (1).

201210111122221 is an equidigital number, since it uses as much as digits as its factorization.

201210111122221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 64, while the sum is 19.

Adding to 201210111122221 its reverse (122221111012102), we get a palindrome (323431222134323).

The spelling of 201210111122221 in words is "two hundred one trillion, two hundred ten billion, one hundred eleven million, one hundred twenty-two thousand, two hundred twenty-one".