181604201 has 2 divisors, whose sum is σ = 181604202. Its totient is φ = 181604200.

The previous prime is 181604197. The next prime is 181604209. The reversal of 181604201 is 102406181.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 168091225 + 13512976 = 12965^2 + 3676^2 .

It is a cyclic number.

It is not a de Polignac number, because 181604201 - 2² = 181604197 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (181604209) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 90802100 + 90802101.

It is an arithmetic number, because the mean of its divisors is an integer number (90802101).

Almost surely, 2^181604201 is an apocalyptic number.

It is an amenable number.

181604201 is a deficient number, since it is larger than the sum of its proper divisors (1).

181604201 is an equidigital number, since it uses as much as digits as its factorization.

181604201 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 384, while the sum is 23.

The square root of 181604201 is about 13476.0602922367. The cubic root of 181604201 is about 566.2940043804.

The spelling of 181604201 in words is "one hundred eighty-one million, six hundred four thousand, two hundred one".