131331521 has 2 divisors, whose sum is σ = 131331522. Its totient is φ = 131331520.

The previous prime is 131331493. The next prime is 131331559. The reversal of 131331521 is 125133131.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 120209296 + 11122225 = 10964^2 + 3335^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-131331521 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 131331493 and 131331502.

It is not a weakly prime, because it can be changed into another prime (131361521) 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 as a sum of consecutive naturals, namely, 65665760 + 65665761.

It is an arithmetic number, because the mean of its divisors is an integer number (65665761).

Almost surely, 2^131331521 is an apocalyptic number.

It is an amenable number.

131331521 is a deficient number, since it is larger than the sum of its proper divisors (1).

131331521 is an equidigital number, since it uses as much as digits as its factorization.

131331521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 270, while the sum is 20.

The square root of 131331521 is about 11459.9965532281. The cubic root of 131331521 is about 508.3033726915.

Adding to 131331521 its reverse (125133131), we get a palindrome (256464652).

The spelling of 131331521 in words is "one hundred thirty-one million, three hundred thirty-one thousand, five hundred twenty-one".