211110009991 has 2 divisors, whose sum is σ = 211110009992. Its totient is φ = 211110009990.

The previous prime is 211110009989. The next prime is 211110010141. The reversal of 211110009991 is 199900011112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 211110009991 - 2¹ = 211110009989 is a prime.

Together with 211110009989, 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 (211110009911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105555004995 + 105555004996.

It is an arithmetic number, because the mean of its divisors is an integer number (105555004996).

Almost surely, 2^211110009991 is an apocalyptic number.

211110009991 is a deficient number, since it is larger than the sum of its proper divisors (1).

211110009991 is an equidigital number, since it uses as much as digits as its factorization.

211110009991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1458, while the sum is 34.

The spelling of 211110009991 in words is "two hundred eleven billion, one hundred ten million, nine thousand, nine hundred ninety-one".