11211019991 has 2 divisors, whose sum is σ = 11211019992. Its totient is φ = 11211019990.

The previous prime is 11211019969. The next prime is 11211020003. The reversal of 11211019991 is 19991011211.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 11211019991 - 2²⁶ = 11143911127 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11211019961) 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, 5605509995 + 5605509996.

It is an arithmetic number, because the mean of its divisors is an integer number (5605509996).

Almost surely, 2^11211019991 is an apocalyptic number.

11211019991 is a deficient number, since it is larger than the sum of its proper divisors (1).

11211019991 is an equidigital number, since it uses as much as digits as its factorization.

11211019991 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 35.

The spelling of 11211019991 in words is "eleven billion, two hundred eleven million, nineteen thousand, nine hundred ninety-one".