181361549 has 8 divisors (see below), whose sum is σ = 182769048. Its totient is φ = 179959360.

The previous prime is 181361539. The next prime is 181361561. The reversal of 181361549 is 945163181.

It can be written as a sum of positive squares in 4 ways, for example, as 16752649 + 164608900 = 4093^2 + 12830^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 181361549 - 2⁸ = 181361293 is a prime.

It is a super-2 number, since 2×181361549² = 65784022911358802, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (181361519) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 89819 + ... + 91815.

It is an arithmetic number, because the mean of its divisors is an integer number (22846131).

Almost surely, 2^181361549 is an apocalyptic number.

It is an amenable number.

181361549 is a deficient number, since it is larger than the sum of its proper divisors (1407499).

181361549 is a wasteful number, since it uses less digits than its factorization.

181361549 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2655.

The product of its digits is 25920, while the sum is 38.

The square root of 181361549 is about 13467.0542064700. The cubic root of 181361549 is about 566.0416724427.

The spelling of 181361549 in words is "one hundred eighty-one million, three hundred sixty-one thousand, five hundred forty-nine".