11111221123 has 2 divisors, whose sum is σ = 11111221124. Its totient is φ = 11111221122.

The previous prime is 11111221103. The next prime is 11111221127. The reversal of 11111221123 is 32112211111.

It is a happy number.

11111221123 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 11111221123 - 2⁹ = 11111220611 is a prime.

It is a super-4 number, since 4×11111221123⁴ (a number of 41 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is a junction number, because it is equal to n+sod(n) for n = 11111221097 and 11111221106.

It is not a weakly prime, because it can be changed into another prime (11111221127) 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, 5555610561 + 5555610562.

It is an arithmetic number, because the mean of its divisors is an integer number (5555610562).

Almost surely, 2^11111221123 is an apocalyptic number.

11111221123 is a deficient number, since it is larger than the sum of its proper divisors (1).

11111221123 is an equidigital number, since it uses as much as digits as its factorization.

11111221123 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 24, while the sum is 16.

Adding to 11111221123 its reverse (32112211111), we get a palindrome (43223432234).

The spelling of 11111221123 in words is "eleven billion, one hundred eleven million, two hundred twenty-one thousand, one hundred twenty-three".