131515309 has 2 divisors, whose sum is σ = 131515310. Its totient is φ = 131515308.

The previous prime is 131515303. The next prime is 131515327. The reversal of 131515309 is 903515131.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 77492809 + 54022500 = 8803^2 + 7350^2 .

It is an emirp because it is prime and its reverse (903515131) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 131515309 - 2⁵ = 131515277 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (131515303) 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, 65757654 + 65757655.

It is an arithmetic number, because the mean of its divisors is an integer number (65757655).

Almost surely, 2^131515309 is an apocalyptic number.

It is an amenable number.

131515309 is a deficient number, since it is larger than the sum of its proper divisors (1).

131515309 is an equidigital number, since it uses as much as digits as its factorization.

131515309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2025, while the sum is 28.

The square root of 131515309 is about 11468.0124258740. The cubic root of 131515309 is about 508.5403721958.

The spelling of 131515309 in words is "one hundred thirty-one million, five hundred fifteen thousand, three hundred nine".