1231118616 has 128 divisors (see below), whose sum is σ = 3805401600. Its totient is φ = 323205120.

The previous prime is 1231118587. The next prime is 1231118617. The reversal of 1231118616 is 6168111321.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1231118617) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 525175 + ... + 527513.

It is an arithmetic number, because the mean of its divisors is an integer number (29729700).

Almost surely, 2^1231118616 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1231118616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1902700800).

1231118616 is an abundant number, since it is smaller than the sum of its proper divisors (2574282984).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1231118616 is a wasteful number, since it uses less digits than its factorization.

1231118616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2609 (or 2605 counting only the distinct ones).

The product of its digits is 1728, while the sum is 30.

The square root of 1231118616 is about 35087.2999246166. The cubic root of 1231118616 is about 1071.7659765196.

Adding to 1231118616 its reverse (6168111321), we get a palindrome (7399229937).

The spelling of 1231118616 in words is "one billion, two hundred thirty-one million, one hundred eighteen thousand, six hundred sixteen".