131809169 has 2 divisors, whose sum is σ = 131809170. Its totient is φ = 131809168.

The previous prime is 131809163. The next prime is 131809199. The reversal of 131809169 is 961908131.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 131790400 + 18769 = 11480^2 + 137^2 .

It is an emirp because it is prime and its reverse (961908131) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 131809169 - 2¹² = 131805073 is a prime.

It is a super-2 number, since 2×131809169² = 34747314064941122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (131809163) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65904584 + 65904585.

It is an arithmetic number, because the mean of its divisors is an integer number (65904585).

Almost surely, 2^131809169 is an apocalyptic number.

It is an amenable number.

131809169 is a deficient number, since it is larger than the sum of its proper divisors (1).

131809169 is an equidigital number, since it uses as much as digits as its factorization.

131809169 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11664, while the sum is 38.

The square root of 131809169 is about 11480.8174360539. The cubic root of 131809169 is about 508.9188541367.

The spelling of 131809169 in words is "one hundred thirty-one million, eight hundred nine thousand, one hundred sixty-nine".