181409 has 2 divisors, whose sum is σ = 181410. Its totient is φ = 181408.

The previous prime is 181399. The next prime is 181421. The reversal of 181409 is 904181.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 180625 + 784 = 425^2 + 28^2 .

It is an emirp because it is prime and its reverse (904181) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 181409 - 2¹⁶ = 115873 is a prime.

It is a Chen prime.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 181409.

It is not a weakly prime, because it can be changed into another prime (181439) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 90704 + 90705.

It is an arithmetic number, because the mean of its divisors is an integer number (90705).

2¹⁸¹⁴⁰⁹ is an apocalyptic number.

It is an amenable number.

181409 is a deficient number, since it is larger than the sum of its proper divisors (1).

181409 is an equidigital number, since it uses as much as digits as its factorization.

181409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 288, while the sum is 23.

The square root of 181409 is about 425.9213542428. The cubic root of 181409 is about 56.6091034066.

The spelling of 181409 in words is "one hundred eighty-one thousand, four hundred nine".