12211121001991 has 2 divisors, whose sum is σ = 12211121001992. Its totient is φ = 12211121001990.

The previous prime is 12211121001983. The next prime is 12211121002103. The reversal of 12211121001991 is 19910012111221.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 12211121001991 - 2³ = 12211121001983 is a prime.

It is a super-3 number, since 3×12211121001991³ (a number of 40 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12211121001901) 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, 6105560500995 + 6105560500996.

It is an arithmetic number, because the mean of its divisors is an integer number (6105560500996).

Almost surely, 2^{12211121001991} is an apocalyptic number.

12211121001991 is a deficient number, since it is larger than the sum of its proper divisors (1).

12211121001991 is an equidigital number, since it uses as much as digits as its factorization.

12211121001991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 648, while the sum is 31.

The spelling of 12211121001991 in words is "twelve trillion, two hundred eleven billion, one hundred twenty-one million, one thousand, nine hundred ninety-one".