131512321 has 4 divisors (see below), whose sum is σ = 137230272. Its totient is φ = 125794372.

The previous prime is 131512307. The next prime is 131512331. The reversal of 131512321 is 123215131.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-131512321 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (131512301) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 2858941 + ... + 2858986.

It is an arithmetic number, because the mean of its divisors is an integer number (34307568).

Almost surely, 2^131512321 is an apocalyptic number.

It is an amenable number.

131512321 is a deficient number, since it is larger than the sum of its proper divisors (5717951).

131512321 is an equidigital number, since it uses as much as digits as its factorization.

131512321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5717950.

The product of its digits is 180, while the sum is 19.

The square root of 131512321 is about 11467.8821497258. The cubic root of 131512321 is about 508.5365208567.

Adding to 131512321 its reverse (123215131), we get a palindrome (254727452).

The spelling of 131512321 in words is "one hundred thirty-one million, five hundred twelve thousand, three hundred twenty-one".