233561 has 4 divisors (see below), whose sum is σ = 234624. Its totient is φ = 232500.

The previous prime is 233557. The next prime is 233591. The reversal of 233561 is 165332.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 233561 - 2² = 233557 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (233551) 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, 65 + ... + 686.

It is an arithmetic number, because the mean of its divisors is an integer number (58656).

2²³³⁵⁶¹ is an apocalyptic number.

It is an amenable number.

233561 is a deficient number, since it is larger than the sum of its proper divisors (1063).

233561 is an equidigital number, since it uses as much as digits as its factorization.

233561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1062.

The product of its digits is 540, while the sum is 20.

The square root of 233561 is about 483.2814914726. The cubic root of 233561 is about 61.5838414074.

Adding to 233561 its reverse (165332), we get a palindrome (398893).

The spelling of 233561 in words is "two hundred thirty-three thousand, five hundred sixty-one".