11111911111811 has 2 divisors, whose sum is σ = 11111911111812. Its totient is φ = 11111911111810.

The previous prime is 11111911111801. The next prime is 11111911111883. The reversal of 11111911111811 is 11811111911111.

It is a m-pointer prime, because the next prime (11111911111883) can be obtained adding 11111911111811 to its product of digits (72).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 11111911111811 - 2¹⁴ = 11111911095427 is a prime.

It is not a weakly prime, because it can be changed into another prime (11111911111801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5555955555905 + 5555955555906.

It is an arithmetic number, because the mean of its divisors is an integer number (5555955555906).

Almost surely, 2^{11111911111811} is an apocalyptic number.

11111911111811 is a deficient number, since it is larger than the sum of its proper divisors (1).

11111911111811 is an equidigital number, since it uses as much as digits as its factorization.

11111911111811 is an evil number, because the sum of its binary digits is even.

The product of its digits is 72, while the sum is 29.

The spelling of 11111911111811 in words is "eleven trillion, one hundred eleven billion, nine hundred eleven million, one hundred eleven thousand, eight hundred eleven".