1311531320 has 32 divisors (see below), whose sum is σ = 3219214320. Its totient is φ = 476920320.

The previous prime is 1311531313. The next prime is 1311531337. The reversal of 1311531320 is 231351131.

It is a super-2 number, since 2×1311531320² = 3440228806681884800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 1311531292 and 1311531301.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 1489937 + ... + 1490816.

Almost surely, 2^1311531320 is an apocalyptic number.

1311531320 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1311531320 is an abundant number, since it is smaller than the sum of its proper divisors (1907683000).

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

1311531320 is a wasteful number, since it uses less digits than its factorization.

1311531320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2980775 (or 2980771 counting only the distinct ones).

The product of its (nonzero) digits is 270, while the sum is 20.

The square root of 1311531320 is about 36215.0703437119. The cubic root of 1311531320 is about 1094.6103629589.

Adding to 1311531320 its reverse (231351131), we get a palindrome (1542882451).

The spelling of 1311531320 in words is "one billion, three hundred eleven million, five hundred thirty-one thousand, three hundred twenty".