210101199991 has 2 divisors, whose sum is σ = 210101199992. Its totient is φ = 210101199990.

The previous prime is 210101199977. The next prime is 210101200003. The reversal of 210101199991 is 199991101012.

210101199991 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 210101199991 - 2⁷ = 210101199863 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (210101199391) 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, 105050599995 + 105050599996.

It is an arithmetic number, because the mean of its divisors is an integer number (105050599996).

Almost surely, 2^210101199991 is an apocalyptic number.

210101199991 is a deficient number, since it is larger than the sum of its proper divisors (1).

210101199991 is an equidigital number, since it uses as much as digits as its factorization.

210101199991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 13122, while the sum is 43.

The spelling of 210101199991 in words is "two hundred ten billion, one hundred one million, one hundred ninety-nine thousand, nine hundred ninety-one".