1311031320 has 128 divisors (see below), whose sum is σ = 4038854400. Its totient is φ = 340314624.

The previous prime is 1311031297. The next prime is 1311031361. The reversal of 1311031320 is 231301131.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 1311031320.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 883299 + ... + 884781.

It is an arithmetic number, because the mean of its divisors is an integer number (31553550).

Almost surely, 2^1311031320 is an apocalyptic number.

1311031320 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1311031320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2019427200).

1311031320 is an abundant number, since it is smaller than the sum of its proper divisors (2727823080).

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

1311031320 is a wasteful number, since it uses less digits than its factorization.

1311031320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1689 (or 1685 counting only the distinct ones).

The product of its (nonzero) digits is 54, while the sum is 15.

The square root of 1311031320 is about 36208.1664821626. The cubic root of 1311031320 is about 1094.4712444749.

Adding to 1311031320 its reverse (231301131), we get a palindrome (1542332451).

The spelling of 1311031320 in words is "one billion, three hundred eleven million, thirty-one thousand, three hundred twenty".