161845 has 4 divisors (see below), whose sum is σ = 194220. Its totient is φ = 129472.

The previous prime is 161839. The next prime is 161869. The reversal of 161845 is 548161.

161845 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It can be written as a sum of positive squares in 2 ways, for example, as 27889 + 133956 = 167^2 + 366^2 .

It is a cyclic number.

It is not a de Polignac number, because 161845 - 2⁷ = 161717 is a prime.

It is a plaindrome in base 13.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16180 + ... + 16189.

It is an arithmetic number, because the mean of its divisors is an integer number (48555).

2¹⁶¹⁸⁴⁵ is an apocalyptic number.

It is an amenable number.

161845 is a deficient number, since it is larger than the sum of its proper divisors (32375).

161845 is an equidigital number, since it uses as much as digits as its factorization.

161845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32374.

The product of its digits is 960, while the sum is 25.

The square root of 161845 is about 402.2996395723. The cubic root of 161845 is about 54.4962262067.

The spelling of 161845 in words is "one hundred sixty-one thousand, eight hundred forty-five".