1131211111 has 4 divisors (see below), whose sum is σ = 1167701824. Its totient is φ = 1094720400.

The previous prime is 1131211099. The next prime is 1131211117. The reversal of 1131211111 is 1111121311.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1131211111 - 2⁵ = 1131211079 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1131211091 and 1131211100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1131211117) 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 in 3 ways as a sum of consecutive naturals, for example, 18245310 + ... + 18245371.

It is an arithmetic number, because the mean of its divisors is an integer number (291925456).

Almost surely, 2^1131211111 is an apocalyptic number.

1131211111 is a deficient number, since it is larger than the sum of its proper divisors (36490713).

1131211111 is an equidigital number, since it uses as much as digits as its factorization.

1131211111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36490712.

The product of its digits is 6, while the sum is 13.

The square root of 1131211111 is about 33633.4819933946. The cubic root of 1131211111 is about 1041.9524193481.

Adding to 1131211111 its reverse (1111121311), we get a palindrome (2242332422).

The spelling of 1131211111 in words is "one billion, one hundred thirty-one million, two hundred eleven thousand, one hundred eleven".