111220122111991 has 2 divisors, whose sum is σ = 111220122111992. Its totient is φ = 111220122111990.

The previous prime is 111220122111971. The next prime is 111220122112049. The reversal of 111220122111991 is 199111221022111.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 111220122111991 - 2¹⁵ = 111220122079223 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (111220122111971) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55610061055995 + 55610061055996.

It is an arithmetic number, because the mean of its divisors is an integer number (55610061055996).

Almost surely, 2^{111220122111991} is an apocalyptic number.

111220122111991 is a deficient number, since it is larger than the sum of its proper divisors (1).

111220122111991 is an equidigital number, since it uses as much as digits as its factorization.

111220122111991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1296, while the sum is 34.

The spelling of 111220122111991 in words is "one hundred eleven trillion, two hundred twenty billion, one hundred twenty-two million, one hundred eleven thousand, nine hundred ninety-one".