131306209 has 2 divisors, whose sum is σ = 131306210. Its totient is φ = 131306208.

The previous prime is 131306179. The next prime is 131306233. The reversal of 131306209 is 902603131.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 82864609 + 48441600 = 9103^2 + 6960^2 .

It is a cyclic number.

It is not a de Polignac number, because 131306209 - 2¹³ = 131298017 is a prime.

It is not a weakly prime, because it can be changed into another prime (131306299) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65653104 + 65653105.

It is an arithmetic number, because the mean of its divisors is an integer number (65653105).

Almost surely, 2^131306209 is an apocalyptic number.

It is an amenable number.

131306209 is a deficient number, since it is larger than the sum of its proper divisors (1).

131306209 is an equidigital number, since it uses as much as digits as its factorization.

131306209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 972, while the sum is 25.

The square root of 131306209 is about 11458.8921366771. The cubic root of 131306209 is about 508.2707148762.

The spelling of 131306209 in words is "one hundred thirty-one million, three hundred six thousand, two hundred nine".