131521515 has 16 divisors (see below), whose sum is σ = 221510400. Its totient is φ = 66452832.

The previous prime is 131521501. The next prime is 131521531. The reversal of 131521515 is 515125131.

It is not a de Polignac number, because 131521515 - 2⁵ = 131521483 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 230455 + ... + 231024.

It is an arithmetic number, because the mean of its divisors is an integer number (13844400).

Almost surely, 2^131521515 is an apocalyptic number.

131521515 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

131521515 is a deficient number, since it is larger than the sum of its proper divisors (89988885).

131521515 is a wasteful number, since it uses less digits than its factorization.

131521515 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 461506.

The product of its digits is 750, while the sum is 24.

The square root of 131521515 is about 11468.2830013913. The cubic root of 131521515 is about 508.5483711427.

Adding to 131521515 its reverse (515125131), we get a palindrome (646646646).

The spelling of 131521515 in words is "one hundred thirty-one million, five hundred twenty-one thousand, five hundred fifteen".