549818161 has 2 divisors, whose sum is σ = 549818162. Its totient is φ = 549818160.

The previous prime is 549818153. The next prime is 549818183. The reversal of 549818161 is 161818945.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 531025936 + 18792225 = 23044^2 + 4335^2 .

It is a cyclic number.

It is not a de Polignac number, because 549818161 - 2³ = 549818153 is a prime.

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

It is not a weakly prime, because it can be changed into another prime (549818461) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 274909080 + 274909081.

It is an arithmetic number, because the mean of its divisors is an integer number (274909081).

Almost surely, 2^549818161 is an apocalyptic number.

It is an amenable number.

549818161 is a deficient number, since it is larger than the sum of its proper divisors (1).

549818161 is an equidigital number, since it uses as much as digits as its factorization.

549818161 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 69120, while the sum is 43.

The square root of 549818161 is about 23448.2016581230. The cubic root of 549818161 is about 819.2309669749.

The spelling of 549818161 in words is "five hundred forty-nine million, eight hundred eighteen thousand, one hundred sixty-one".