1311131728 has 10 divisors (see below), whose sum is σ = 2540317754. Its totient is φ = 655565856.

The previous prime is 1311131719. The next prime is 1311131729. The reversal of 1311131728 is 8271311131.

It can be written as a sum of positive squares in only one way, i.e., 1256844304 + 54287424 = 35452^2 + 7368^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1311131696 and 1311131705.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1311131729) 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 as a sum of consecutive naturals, namely, 40972851 + ... + 40972882.

Almost surely, 2^1311131728 is an apocalyptic number.

It is an amenable number.

1311131728 is a deficient number, since it is larger than the sum of its proper divisors (1229186026).

1311131728 is an equidigital number, since it uses as much as digits as its factorization.

1311131728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81945741 (or 81945735 counting only the distinct ones).

The product of its digits is 1008, while the sum is 28.

The square root of 1311131728 is about 36209.5529936507. The cubic root of 1311131728 is about 1094.4991845304.

Adding to 1311131728 its reverse (8271311131), we get a palindrome (9582442859).

The spelling of 1311131728 in words is "one billion, three hundred eleven million, one hundred thirty-one thousand, seven hundred twenty-eight".