11121210999991 has 2 divisors, whose sum is σ = 11121210999992. Its totient is φ = 11121210999990.

The previous prime is 11121210999919. The next prime is 11121211000037. The reversal of 11121210999991 is 19999901212111.

Together with previous prime (11121210999919) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 11121210999991 - 2¹⁹ = 11121210475703 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11121210999901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5560605499995 + 5560605499996.

It is an arithmetic number, because the mean of its divisors is an integer number (5560605499996).

Almost surely, 2^{11121210999991} is an apocalyptic number.

11121210999991 is a deficient number, since it is larger than the sum of its proper divisors (1).

11121210999991 is an equidigital number, since it uses as much as digits as its factorization.

11121210999991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 236196, while the sum is 55.

The spelling of 11121210999991 in words is "eleven trillion, one hundred twenty-one billion, two hundred ten million, nine hundred ninety-nine thousand, nine hundred ninety-one".