111211011111001 has 2 divisors, whose sum is σ = 111211011111002. Its totient is φ = 111211011111000.

The previous prime is 111211011110993. The next prime is 111211011111023. The reversal of 111211011111001 is 100111110112111.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 96743059998025 + 14467951112976 = 9835805^2 + 3803676^2 .

It is a cyclic number.

It is not a de Polignac number, because 111211011111001 - 2³ = 111211011110993 is a prime.

It is not a weakly prime, because it can be changed into another prime (111211011111041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55605505555500 + 55605505555501.

It is an arithmetic number, because the mean of its divisors is an integer number (55605505555501).

Almost surely, 2^{111211011111001} is an apocalyptic number.

It is an amenable number.

111211011111001 is a deficient number, since it is larger than the sum of its proper divisors (1).

111211011111001 is an equidigital number, since it uses as much as digits as its factorization.

111211011111001 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2, while the sum is 13.

Adding to 111211011111001 its reverse (100111110112111), we get a palindrome (211322121223112).

The spelling of 111211011111001 in words is "one hundred eleven trillion, two hundred eleven billion, eleven million, one hundred eleven thousand, one".