1111211121121 has 2 divisors, whose sum is σ = 1111211121122. Its totient is φ = 1111211121120.

The previous prime is 1111211121107. The next prime is 1111211121221. The reversal of 1111211121121 is 1211211121111.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 936433613025 + 174777508096 = 967695^2 + 418064^2 .

It is a cyclic number.

It is not a de Polignac number, because 1111211121121 - 2¹³ = 1111211112929 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1111211121095 and 1111211121104.

It is not a weakly prime, because it can be changed into another prime (1111211121221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 555605560560 + 555605560561.

It is an arithmetic number, because the mean of its divisors is an integer number (555605560561).

Almost surely, 2^{1111211121121} is an apocalyptic number.

It is an amenable number.

1111211121121 is a deficient number, since it is larger than the sum of its proper divisors (1).

1111211121121 is an equidigital number, since it uses as much as digits as its factorization.

1111211121121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8, while the sum is 16.

Adding to 1111211121121 its reverse (1211211121111), we get a palindrome (2322422242232).

The spelling of 1111211121121 in words is "one trillion, one hundred eleven billion, two hundred eleven million, one hundred twenty-one thousand, one hundred twenty-one".