181838363809 has 2 divisors, whose sum is σ = 181838363810. Its totient is φ = 181838363808.

The previous prime is 181838363767. The next prime is 181838363869. The reversal of 181838363809 is 908363838181.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 127661146209 + 54177217600 = 357297^2 + 232760^2 .

It is a cyclic number.

It is not a de Polignac number, because 181838363809 - 2¹⁵ = 181838331041 is a prime.

It is not a weakly prime, because it can be changed into another prime (181838363869) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 90919181904 + 90919181905.

It is an arithmetic number, because the mean of its divisors is an integer number (90919181905).

Almost surely, 2^181838363809 is an apocalyptic number.

It is an amenable number.

181838363809 is a deficient number, since it is larger than the sum of its proper divisors (1).

181838363809 is an equidigital number, since it uses as much as digits as its factorization.

181838363809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5971968, while the sum is 58.

The spelling of 181838363809 in words is "one hundred eighty-one billion, eight hundred thirty-eight million, three hundred sixty-three thousand, eight hundred nine".