131604409 has 2 divisors, whose sum is σ = 131604410. Its totient is φ = 131604408.

The previous prime is 131604391. The next prime is 131604437. The reversal of 131604409 is 904406131.

It is an a-pointer prime, because the next prime (131604437) can be obtained adding 131604409 to its sum of digits (28).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 116704809 + 14899600 = 10803^2 + 3860^2 .

It is an emirp because it is prime and its reverse (904406131) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 131604409 - 2⁵ = 131604377 is a prime.

It is not a weakly prime, because it can be changed into another prime (131601409) 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, 65802204 + 65802205.

It is an arithmetic number, because the mean of its divisors is an integer number (65802205).

Almost surely, 2^131604409 is an apocalyptic number.

It is an amenable number.

131604409 is a deficient number, since it is larger than the sum of its proper divisors (1).

131604409 is an equidigital number, since it uses as much as digits as its factorization.

131604409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2592, while the sum is 28.

The square root of 131604409 is about 11471.8964866320. The cubic root of 131604409 is about 508.6551895475.

The spelling of 131604409 in words is "one hundred thirty-one million, six hundred four thousand, four hundred nine".