131543521 has 4 divisors (see below), whose sum is σ = 131575444. Its totient is φ = 131511600.

The previous prime is 131543483. The next prime is 131543527. The reversal of 131543521 is 125345131.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 125345131 = 17 ⋅7373243.

It can be written as a sum of positive squares in 2 ways, for example, as 70140625 + 61402896 = 8375^2 + 7836^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-131543521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (131543527) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8670 + ... + 18391.

It is an arithmetic number, because the mean of its divisors is an integer number (32893861).

Almost surely, 2^131543521 is an apocalyptic number.

It is an amenable number.

131543521 is a deficient number, since it is larger than the sum of its proper divisors (31923).

131543521 is an equidigital number, since it uses as much as digits as its factorization.

131543521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31922.

The product of its digits is 1800, while the sum is 25.

The square root of 131543521 is about 11469.2423899750. The cubic root of 131543521 is about 508.5767327669.

Adding to 131543521 its reverse (125345131), we get a palindrome (256888652).

The spelling of 131543521 in words is "one hundred thirty-one million, five hundred forty-three thousand, five hundred twenty-one".