210111202111121 has 2 divisors, whose sum is σ = 210111202111122. Its totient is φ = 210111202111120.

The previous prime is 210111202110973. The next prime is 210111202111123. The reversal of 210111202111121 is 121111202111012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 201903893885521 + 8207308225600 = 14209289^2 + 2864840^2 .

It is a cyclic number.

It is not a de Polignac number, because 210111202111121 - 2³⁴ = 210094022241937 is a prime.

Together with 210111202111123, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 210111202111121.

It is not a weakly prime, because it can be changed into another prime (210111202111123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105055601055560 + 105055601055561.

It is an arithmetic number, because the mean of its divisors is an integer number (105055601055561).

Almost surely, 2^{210111202111121} is an apocalyptic number.

It is an amenable number.

210111202111121 is a deficient number, since it is larger than the sum of its proper divisors (1).

210111202111121 is an equidigital number, since it uses as much as digits as its factorization.

210111202111121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16, while the sum is 17.

Adding to 210111202111121 its reverse (121111202111012), we get a palindrome (331222404222133).

The spelling of 210111202111121 in words is "two hundred ten trillion, one hundred eleven billion, two hundred two million, one hundred eleven thousand, one hundred twenty-one".