181630121 has 2 divisors, whose sum is σ = 181630122. Its totient is φ = 181630120.

The previous prime is 181630117. The next prime is 181630129. The reversal of 181630121 is 121036181.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 157226521 + 24403600 = 12539^2 + 4940^2 .

It is a cyclic number.

It is not a de Polignac number, because 181630121 - 2² = 181630117 is a prime.

It is a Sophie Germain prime.

It is an alternating number because its digits alternate between odd and even.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (181630129) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 90815060 + 90815061.

It is an arithmetic number, because the mean of its divisors is an integer number (90815061).

Almost surely, 2^181630121 is an apocalyptic number.

It is an amenable number.

181630121 is a deficient number, since it is larger than the sum of its proper divisors (1).

181630121 is an equidigital number, since it uses as much as digits as its factorization.

181630121 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 181630121 is about 13477.0219633271. The cubic root of 181630121 is about 566.3209450977.

The spelling of 181630121 in words is "one hundred eighty-one million, six hundred thirty thousand, one hundred twenty-one".