181409121 has 12 divisors (see below), whose sum is σ = 262161172. Its totient is φ = 120881376.

The previous prime is 181409083. The next prime is 181409141. The reversal of 181409121 is 121904181.

It can be written as a sum of positive squares in 2 ways, for example, as 65610000 + 115799121 = 8100^2 + 10761^2 .

It is not a de Polignac number, because 181409121 - 2⁹ = 181408609 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (181409141) 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 in 11 ways as a sum of consecutive naturals, for example, 24015 + ... + 30651.

Almost surely, 2^181409121 is an apocalyptic number.

It is an amenable number.

181409121 is a deficient number, since it is larger than the sum of its proper divisors (80752051).

181409121 is a wasteful number, since it uses less digits than its factorization.

181409121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9680 (or 9677 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 27.

The square root of 181409121 is about 13468.8203269626. The cubic root of 181409121 is about 566.0911599269.

It can be divided in two parts, 18140 and 9121, that added together give a triangular number (27261 = T₂₃₃).

The spelling of 181409121 in words is "one hundred eighty-one million, four hundred nine thousand, one hundred twenty-one".