11211199991 has 2 divisors, whose sum is σ = 11211199992. Its totient is φ = 11211199990.

The previous prime is 11211199973. The next prime is 11211200009. The reversal of 11211199991 is 19999111211.

It is a balanced prime because it is at equal distance from previous prime (11211199973) and next prime (11211200009).

It is a cyclic number.

It is not a de Polignac number, because 11211199991 - 2¹⁸ = 11210937847 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11211199091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5605599995 + 5605599996.

It is an arithmetic number, because the mean of its divisors is an integer number (5605599996).

Almost surely, 2^11211199991 is an apocalyptic number.

11211199991 is a deficient number, since it is larger than the sum of its proper divisors (1).

11211199991 is an equidigital number, since it uses as much as digits as its factorization.

11211199991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13122, while the sum is 44.

The spelling of 11211199991 in words is "eleven billion, two hundred eleven million, one hundred ninety-nine thousand, nine hundred ninety-one".