181085631 has 4 divisors (see below), whose sum is σ = 241447512. Its totient is φ = 120723752.

The previous prime is 181085587. The next prime is 181085669. The reversal of 181085631 is 136580181.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 181085631 - 2⁹ = 181085119 is a prime.

It is a super-2 number, since 2×181085631² = 65584011509336322, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 181085592 and 181085601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (181085431) 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 3 ways as a sum of consecutive naturals, for example, 30180936 + ... + 30180941.

It is an arithmetic number, because the mean of its divisors is an integer number (60361878).

Almost surely, 2^181085631 is an apocalyptic number.

181085631 is a deficient number, since it is larger than the sum of its proper divisors (60361881).

181085631 is an equidigital number, since it uses as much as digits as its factorization.

181085631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60361880.

The product of its (nonzero) digits is 5760, while the sum is 33.

The square root of 181085631 is about 13456.8061218106. The cubic root of 181085631 is about 565.7544738292.

The spelling of 181085631 in words is "one hundred eighty-one million, eighty-five thousand, six hundred thirty-one".