121212210191 has 2 divisors, whose sum is σ = 121212210192. Its totient is φ = 121212210190.

The previous prime is 121212210143. The next prime is 121212210227. The reversal of 121212210191 is 191012212121.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-121212210191 is a prime.

It is a zygodrome in base 2.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121212210491) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60606105095 + 60606105096.

It is an arithmetic number, because the mean of its divisors is an integer number (60606105096).

Almost surely, 2^121212210191 is an apocalyptic number.

121212210191 is a deficient number, since it is larger than the sum of its proper divisors (1).

121212210191 is an equidigital number, since it uses as much as digits as its factorization.

121212210191 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 23.

The spelling of 121212210191 in words is "one hundred twenty-one billion, two hundred twelve million, two hundred ten thousand, one hundred ninety-one".