1311322320 has 720 divisors, whose sum is σ = 5821770240. Its totient is φ = 261273600.

The previous prime is 1311322283. The next prime is 1311322321. The reversal of 1311322320 is 232231131.

1311322320 is a `hidden beast` number, since 1 + 311 + 32 + 2 + 320 = 666.

It is a tau number, because it is divible by the number of its divisors (720).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 1311322293 and 1311322302.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1311322321) by changing a digit.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 12030426 + ... + 12030534.

It is an arithmetic number, because the mean of its divisors is an integer number (8085792).

Almost surely, 2^1311322320 is an apocalyptic number.

1311322320 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 1311322320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2910885120).

1311322320 is an abundant number, since it is smaller than the sum of its proper divisors (4510447920).

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

1311322320 is a wasteful number, since it uses less digits than its factorization.

1311322320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 184 (or 168 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

The square root of 1311322320 is about 36212.1846896870. The cubic root of 1311322320 is about 1094.5522157342.

Adding to 1311322320 its reverse (232231131), we get a palindrome (1543553451).

The spelling of 1311322320 in words is "one billion, three hundred eleven million, three hundred twenty-two thousand, three hundred twenty".