11111111129 has 2 divisors, whose sum is σ = 11111111130. Its totient is φ = 11111111128.

The previous prime is 11111111113. The next prime is 11111111131. The reversal of 11111111129 is 92111111111.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10870147600 + 240963529 = 104260^2 + 15523^2 .

It is a cyclic number.

It is not a de Polignac number, because 11111111129 - 2⁴ = 11111111113 is a prime.

Together with 11111111131, it forms a pair of twin primes.

It is a Chen prime.

It is a plaindrome in base 10.

It is a self number, because there is not a number n which added to its sum of digits gives 11111111129.

It is not a weakly prime, because it can be changed into another prime (11111111159) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5555555564 + 5555555565.

It is an arithmetic number, because the mean of its divisors is an integer number (5555555565).

Almost surely, 2^11111111129 is an apocalyptic number.

It is an amenable number.

11111111129 is a deficient number, since it is larger than the sum of its proper divisors (1).

11111111129 is an equidigital number, since it uses as much as digits as its factorization.

11111111129 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18, while the sum is 20.

Subtracting from 11111111129 its product of digits (18), we obtain a palindrome (11111111111).

The spelling of 11111111129 in words is "eleven billion, one hundred eleven million, one hundred eleven thousand, one hundred twenty-nine".