999971000191 has 2 divisors, whose sum is σ = 999971000192. Its totient is φ = 999971000190.

The previous prime is 999971000159. The next prime is 999971000257. The reversal of 999971000191 is 191000179999.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 999971000191 - 2⁵ = 999971000159 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (999971000111) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499985500095 + 499985500096.

It is an arithmetic number, because the mean of its divisors is an integer number (499985500096).

Almost surely, 2^999971000191 is an apocalyptic number.

999971000191 is a deficient number, since it is larger than the sum of its proper divisors (1).

999971000191 is an equidigital number, since it uses as much as digits as its factorization.

999971000191 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 413343, while the sum is 55.

The spelling of 999971000191 in words is "nine hundred ninety-nine billion, nine hundred seventy-one million, one hundred ninety-one", and thus it is an aban number.