131231515 has 8 divisors (see below), whose sum is σ = 157555008. Its totient is φ = 104933760.

The previous prime is 131231431. The next prime is 131231521. The reversal of 131231515 is 515132131.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-131231515 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 7555 + ... + 17875.

It is an arithmetic number, because the mean of its divisors is an integer number (19694376).

Almost surely, 2^131231515 is an apocalyptic number.

131231515 is a deficient number, since it is larger than the sum of its proper divisors (26323493).

131231515 is a wasteful number, since it uses less digits than its factorization.

131231515 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12869.

The product of its digits is 450, while the sum is 22.

The square root of 131231515 is about 11455.6324574421. The cubic root of 131231515 is about 508.1743193995.

Adding to 131231515 its reverse (515132131), we get a palindrome (646363646).

The spelling of 131231515 in words is "one hundred thirty-one million, two hundred thirty-one thousand, five hundred fifteen".