181807121 has 2 divisors, whose sum is σ = 181807122. Its totient is φ = 181807120.

The previous prime is 181807063. The next prime is 181807133. The reversal of 181807121 is 121708181.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 181710400 + 96721 = 13480^2 + 311^2 .

It is a cyclic number.

It is not a de Polignac number, because 181807121 - 2⁶ = 181807057 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (181807141) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 90903560 + 90903561.

It is an arithmetic number, because the mean of its divisors is an integer number (90903561).

Almost surely, 2^181807121 is an apocalyptic number.

It is an amenable number.

181807121 is a deficient number, since it is larger than the sum of its proper divisors (1).

181807121 is an equidigital number, since it uses as much as digits as its factorization.

181807121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 896, while the sum is 29.

The square root of 181807121 is about 13483.5870969116. The cubic root of 181807121 is about 566.5048467971.

The spelling of 181807121 in words is "one hundred eighty-one million, eight hundred seven thousand, one hundred twenty-one".