181491085 has 8 divisors (see below), whose sum is σ = 218175480. Its totient is φ = 144935424.

The previous prime is 181491073. The next prime is 181491109. The reversal of 181491085 is 580194181.

181491085 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 36264484 + 145226601 = 6022^2 + 12051^2 .

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 181491085 - 2²¹ = 179393933 is a prime.

It is a super-3 number, since 3×181491085³ (a number of 26 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 29052 + ... + 34741.

It is an arithmetic number, because the mean of its divisors is an integer number (27271935).

Almost surely, 2^181491085 is an apocalyptic number.

It is an amenable number.

181491085 is a deficient number, since it is larger than the sum of its proper divisors (36684395).

181491085 is an equidigital number, since it uses as much as digits as its factorization.

181491085 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64367.

The product of its (nonzero) digits is 11520, while the sum is 37.

The square root of 181491085 is about 13471.8627145618. The cubic root of 181491085 is about 566.1764039127.

The spelling of 181491085 in words is "one hundred eighty-one million, four hundred ninety-one thousand, eighty-five".