11000020111991 has 2 divisors, whose sum is σ = 11000020111992. Its totient is φ = 11000020111990.

The previous prime is 11000020111957. The next prime is 11000020112087. The reversal of 11000020111991 is 19911102000011.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11000020111991 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 11000020111991.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11000020111391) 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, 5500010055995 + 5500010055996.

It is an arithmetic number, because the mean of its divisors is an integer number (5500010055996).

Almost surely, 2^{11000020111991} is an apocalyptic number.

11000020111991 is a deficient number, since it is larger than the sum of its proper divisors (1).

11000020111991 is an equidigital number, since it uses as much as digits as its factorization.

11000020111991 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 11000020111991 in words is "eleven trillion, twenty million, one hundred eleven thousand, nine hundred ninety-one".