181840181 has 2 divisors, whose sum is σ = 181840182. Its totient is φ = 181840180.

The previous prime is 181840157. The next prime is 181840229. The reversal of 181840181 is 181048181.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 135722500 + 46117681 = 11650^2 + 6791^2 .

It is a cyclic number.

It is not a de Polignac number, because 181840181 - 2⁶ = 181840117 is a prime.

It is a super-2 number, since 2×181840181² = 66131702852225522, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (181840081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 90920090 + 90920091.

It is an arithmetic number, because the mean of its divisors is an integer number (90920091).

Almost surely, 2^181840181 is an apocalyptic number.

It is an amenable number.

181840181 is a deficient number, since it is larger than the sum of its proper divisors (1).

181840181 is an equidigital number, since it uses as much as digits as its factorization.

181840181 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2048, while the sum is 32.

The square root of 181840181 is about 13484.8129760854. The cubic root of 181840181 is about 566.5391826636.

The spelling of 181840181 in words is "one hundred eighty-one million, eight hundred forty thousand, one hundred eighty-one".