1111111813121 has 2 divisors, whose sum is σ = 1111111813122. Its totient is φ = 1111111813120.

The previous prime is 1111111813117. The next prime is 1111111813169. The reversal of 1111111813121 is 1213181111111.

It is a m-pointer prime, because the next prime (1111111813169) can be obtained adding 1111111813121 to its product of digits (48).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1103875929025 + 7235884096 = 1050655^2 + 85064^2 .

It is a cyclic number.

It is not a de Polignac number, because 1111111813121 - 2² = 1111111813117 is a prime.

It is a super-2 number, since 2×1111111813121² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1111111813621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 555555906560 + 555555906561.

It is an arithmetic number, because the mean of its divisors is an integer number (555555906561).

Almost surely, 2^{1111111813121} is an apocalyptic number.

It is an amenable number.

1111111813121 is a deficient number, since it is larger than the sum of its proper divisors (1).

1111111813121 is an equidigital number, since it uses as much as digits as its factorization.

1111111813121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 48, while the sum is 23.

Adding to 1111111813121 its reverse (1213181111111), we get a palindrome (2324292924232).

The spelling of 1111111813121 in words is "one trillion, one hundred eleven billion, one hundred eleven million, eight hundred thirteen thousand, one hundred twenty-one".