1312531515 has 24 divisors (see below), whose sum is σ = 2276033760. Its totient is φ = 699715584.

The previous prime is 1312531511. The next prime is 1312531531. The reversal of 1312531515 is 5151352131.

It is not a de Polignac number, because 1312531515 - 2² = 1312531511 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1312531511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 133819 + ... + 143291.

It is an arithmetic number, because the mean of its divisors is an integer number (94834740).

Almost surely, 2^1312531515 is an apocalyptic number.

1312531515 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1312531515 is a deficient number, since it is larger than the sum of its proper divisors (963502245).

1312531515 is a wasteful number, since it uses less digits than its factorization.

1312531515 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12563 (or 12560 counting only the distinct ones).

The product of its digits is 2250, while the sum is 27.

The square root of 1312531515 is about 36228.8768111847. The cubic root of 1312531515 is about 1094.8885481111. Note that the first 3 decimals are identical.

Adding to 1312531515 its reverse (5151352131), we get a palindrome (6463883646).

The spelling of 1312531515 in words is "one billion, three hundred twelve million, five hundred thirty-one thousand, five hundred fifteen".