10211011991 has 2 divisors, whose sum is σ = 10211011992. Its totient is φ = 10211011990.

The previous prime is 10211011949. The next prime is 10211011997. The reversal of 10211011991 is 19911011201.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 10211011991 - 2⁶ = 10211011927 is a prime.

It is a Sophie Germain prime.

It is a self number, because there is not a number n which added to its sum of digits gives 10211011991.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (10211011997) 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, 5105505995 + 5105505996.

It is an arithmetic number, because the mean of its divisors is an integer number (5105505996).

Almost surely, 2^10211011991 is an apocalyptic number.

10211011991 is a deficient number, since it is larger than the sum of its proper divisors (1).

10211011991 is an equidigital number, since it uses as much as digits as its factorization.

10211011991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 162, while the sum is 26.

The spelling of 10211011991 in words is "ten billion, two hundred eleven million, eleven thousand, nine hundred ninety-one".