161823 has 16 divisors (see below), whose sum is σ = 241920. Its totient is φ = 95616.

The previous prime is 161807. The next prime is 161831. The reversal of 161823 is 328161.

It is not a de Polignac number, because 161823 - 2⁴ = 161807 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 161823.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161873) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 886 + ... + 1052.

It is an arithmetic number, because the mean of its divisors is an integer number (15120).

2¹⁶¹⁸²³ is an apocalyptic number.

161823 is a deficient number, since it is larger than the sum of its proper divisors (80097).

161823 is a wasteful number, since it uses less digits than its factorization.

161823 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 206.

The product of its digits is 288, while the sum is 21.

The square root of 161823 is about 402.2722958395. The cubic root of 161823 is about 54.4937568249.

Adding to 161823 its reverse (328161), we get a palindrome (489984).

The spelling of 161823 in words is "one hundred sixty-one thousand, eight hundred twenty-three".