161831523 has 16 divisors (see below), whose sum is σ = 246871040. Its totient is φ = 92373696.

The previous prime is 161831521. The next prime is 161831533. The reversal of 161831523 is 325138161.

161831523 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 161831523 - 2¹ = 161831521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161831521) 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, 18111 + ... + 25527.

It is an arithmetic number, because the mean of its divisors is an integer number (15429440).

Almost surely, 2^161831523 is an apocalyptic number.

161831523 is a deficient number, since it is larger than the sum of its proper divisors (85039517).

161831523 is a wasteful number, since it uses less digits than its factorization.

161831523 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8466.

The product of its digits is 4320, while the sum is 30.

The square root of 161831523 is about 12721.3019380879. The cubic root of 161831523 is about 544.9471351242.

Adding to 161831523 its reverse (325138161), we get a palindrome (486969684).

The spelling of 161831523 in words is "one hundred sixty-one million, eight hundred thirty-one thousand, five hundred twenty-three".