131181917 has 2 divisors, whose sum is σ = 131181918. Its totient is φ = 131181916.

The previous prime is 131181899. The next prime is 131181923. The reversal of 131181917 is 719181131.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 66765241 + 64416676 = 8171^2 + 8026^2 .

It is a cyclic number.

It is not a de Polignac number, because 131181917 - 2¹⁸ = 130919773 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (131181997) 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, 65590958 + 65590959.

It is an arithmetic number, because the mean of its divisors is an integer number (65590959).

Almost surely, 2^131181917 is an apocalyptic number.

It is an amenable number.

131181917 is a deficient number, since it is larger than the sum of its proper divisors (1).

131181917 is an equidigital number, since it uses as much as digits as its factorization.

131181917 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1512, while the sum is 32.

The square root of 131181917 is about 11453.4674662305. The cubic root of 131181917 is about 508.1102910654.

The spelling of 131181917 in words is "one hundred thirty-one million, one hundred eighty-one thousand, nine hundred seventeen".