131529809 has 4 divisors (see below), whose sum is σ = 131553204. Its totient is φ = 131506416.

The previous prime is 131529803. The next prime is 131529817. The reversal of 131529809 is 908925131.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 908925131 = 733 ⋅1240007.

It can be written as a sum of positive squares in 2 ways, for example, as 22118209 + 109411600 = 4703^2 + 10460^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-131529809 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (131529803) 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 in 3 ways as a sum of consecutive naturals, for example, 2399 + ... + 16395.

It is an arithmetic number, because the mean of its divisors is an integer number (32888301).

Almost surely, 2^131529809 is an apocalyptic number.

It is an amenable number.

131529809 is a deficient number, since it is larger than the sum of its proper divisors (23395).

131529809 is an equidigital number, since it uses as much as digits as its factorization.

131529809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23394.

The product of its (nonzero) digits is 19440, while the sum is 38.

The square root of 131529809 is about 11468.6446016955. The cubic root of 131529809 is about 508.5590609311.

The spelling of 131529809 in words is "one hundred thirty-one million, five hundred twenty-nine thousand, eight hundred nine".