131305309 has 2 divisors, whose sum is σ = 131305310. Its totient is φ = 131305308.

The previous prime is 131305303. The next prime is 131305337. The reversal of 131305309 is 903503131.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 130028409 + 1276900 = 11403^2 + 1130^2 .

It is a cyclic number.

It is not a de Polignac number, because 131305309 - 2⁵ = 131305277 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (131305303) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65652654 + 65652655.

It is an arithmetic number, because the mean of its divisors is an integer number (65652655).

Almost surely, 2^131305309 is an apocalyptic number.

It is an amenable number.

131305309 is a deficient number, since it is larger than the sum of its proper divisors (1).

131305309 is an equidigital number, since it uses as much as digits as its factorization.

131305309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1215, while the sum is 25.

The square root of 131305309 is about 11458.8528657977. The cubic root of 131305309 is about 508.2695536093.

The spelling of 131305309 in words is "one hundred thirty-one million, three hundred five thousand, three hundred nine".