212101121199991 has 2 divisors, whose sum is σ = 212101121199992. Its totient is φ = 212101121199990.

The previous prime is 212101121199983. The next prime is 212101121200019. The reversal of 212101121199991 is 199991121101212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 212101121199991 - 2³ = 212101121199983 is a prime.

It is a super-2 number, since 2×212101121199991² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (212101121199971) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106050560599995 + 106050560599996.

It is an arithmetic number, because the mean of its divisors is an integer number (106050560599996).

Almost surely, 2^{212101121199991} is an apocalyptic number.

212101121199991 is a deficient number, since it is larger than the sum of its proper divisors (1).

212101121199991 is an equidigital number, since it uses as much as digits as its factorization.

212101121199991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 52488, while the sum is 49.

The spelling of 212101121199991 in words is "two hundred twelve trillion, one hundred one billion, one hundred twenty-one million, one hundred ninety-nine thousand, nine hundred ninety-one".