131242409 has 2 divisors, whose sum is σ = 131242410. Its totient is φ = 131242408.

The previous prime is 131242399. The next prime is 131242417. The reversal of 131242409 is 904242131.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 118483225 + 12759184 = 10885^2 + 3572^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-131242409 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (131244409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65621204 + 65621205.

It is an arithmetic number, because the mean of its divisors is an integer number (65621205).

Almost surely, 2^131242409 is an apocalyptic number.

It is an amenable number.

131242409 is a deficient number, since it is larger than the sum of its proper divisors (1).

131242409 is an equidigital number, since it uses as much as digits as its factorization.

131242409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1728, while the sum is 26.

The square root of 131242409 is about 11456.1079341982. The cubic root of 131242409 is about 508.1883808030.

The spelling of 131242409 in words is "one hundred thirty-one million, two hundred forty-two thousand, four hundred nine".