123558 has 8 divisors (see below), whose sum is σ = 247128. Its totient is φ = 41184.

The previous prime is 123553. The next prime is 123581. The reversal of 123558 is 855321.

It is a sphenic number, since it is the product of 3 distinct primes.

123558 is an admirable number.

It is a Smith number, since the sum of its digits (24) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a plaindrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123551) by changing a digit.

123558 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10291 + ... + 10302.

It is an arithmetic number, because the mean of its divisors is an integer number (30891).

2¹²³⁵⁵⁸ is an apocalyptic number.

123558 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

123558 is a wasteful number, since it uses less digits than its factorization.

123558 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20598.

The product of its digits is 1200, while the sum is 24.

The square root of 123558 is about 351.5081791367. The cubic root of 123558 is about 49.8069892289.

Adding to 123558 its reverse (855321), we get a palindrome (978879).

It can be divided in two parts, 12 and 3558, that added together give a triangular number (3570 = T₈₄).

The spelling of 123558 in words is "one hundred twenty-three thousand, five hundred fifty-eight".