161538 has 32 divisors (see below), whose sum is σ = 369600. Its totient is φ = 46656.

The previous prime is 161531. The next prime is 161543. The reversal of 161538 is 835161.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (161531) 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, 1428 + ... + 1536.

It is an arithmetic number, because the mean of its divisors is an integer number (11550).

2¹⁶¹⁵³⁸ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 161538, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (184800).

161538 is an abundant number, since it is smaller than the sum of its proper divisors (208062).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

161538 is a wasteful number, since it uses less digits than its factorization.

161538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 146.

The product of its digits is 720, while the sum is 24.

The square root of 161538 is about 401.9179020646. The cubic root of 161538 is about 54.4617468570.

Adding to 161538 its reverse (835161), we get a palindrome (996699).

It can be divided in two parts, 16153 and 8, that added together give a palindrome (16161).

The spelling of 161538 in words is "one hundred sixty-one thousand, five hundred thirty-eight".