181136506409 has 2 divisors, whose sum is σ = 181136506410. Its totient is φ = 181136506408.

The previous prime is 181136506393. The next prime is 181136506451. The reversal of 181136506409 is 904605631181.

181136506409 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 167610816409 + 13525690000 = 409403^2 + 116300^2 .

It is a cyclic number.

It is not a de Polignac number, because 181136506409 - 2⁴ = 181136506393 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 181136506409.

It is not a weakly prime, because it can be changed into another prime (181136506459) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 90568253204 + 90568253205.

It is an arithmetic number, because the mean of its divisors is an integer number (90568253205).

Almost surely, 2^181136506409 is an apocalyptic number.

It is an amenable number.

181136506409 is a deficient number, since it is larger than the sum of its proper divisors (1).

181136506409 is an equidigital number, since it uses as much as digits as its factorization.

181136506409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 155520, while the sum is 44.

The spelling of 181136506409 in words is "one hundred eighty-one billion, one hundred thirty-six million, five hundred six thousand, four hundred nine".