1231231111 has 4 divisors (see below), whose sum is σ = 1343161224. Its totient is φ = 1119301000.

The previous prime is 1231231087. The next prime is 1231231121. The reversal of 1231231111 is 1111321321.

It is a happy number.

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 1231231111 - 2¹⁵ = 1231198343 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1231231121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 55965040 + ... + 55965061.

It is an arithmetic number, because the mean of its divisors is an integer number (335790306).

Almost surely, 2^1231231111 is an apocalyptic number.

1231231111 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1231231111 is a deficient number, since it is larger than the sum of its proper divisors (111930113).

1231231111 is a wasteful number, since it uses less digits than its factorization.

1231231111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111930112.

The product of its digits is 36, while the sum is 16.

The square root of 1231231111 is about 35088.9029609077. The cubic root of 1231231111 is about 1071.7986201766.

Adding to 1231231111 its reverse (1111321321), we get a palindrome (2342552432).

The spelling of 1231231111 in words is "one billion, two hundred thirty-one million, two hundred thirty-one thousand, one hundred eleven".