163531 has 4 divisors (see below), whose sum is σ = 169200. Its totient is φ = 157864.

The previous prime is 163517. The next prime is 163543. The reversal of 163531 is 135361.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 135361 = 223 ⋅607.

It is a cyclic number.

It is not a de Polignac number, because 163531 - 2⁷ = 163403 is a prime.

It is a super-2 number, since 2×163531² = 53484775922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 163499 and 163508.

It is not an unprimeable number, because it can be changed into a prime (163561) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2791 + ... + 2848.

It is an arithmetic number, because the mean of its divisors is an integer number (42300).

2¹⁶³⁵³¹ is an apocalyptic number.

163531 is a deficient number, since it is larger than the sum of its proper divisors (5669).

163531 is an equidigital number, since it uses as much as digits as its factorization.

163531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5668.

The product of its digits is 270, while the sum is 19.

The square root of 163531 is about 404.3896635672. The cubic root of 163531 is about 54.6848087383.

Adding to 163531 its reverse (135361), we get a palindrome (298892).

The spelling of 163531 in words is "one hundred sixty-three thousand, five hundred thirty-one".