123659 has 4 divisors (see below), whose sum is σ = 127680. Its totient is φ = 119640.

The previous prime is 123653. The next prime is 123661. The reversal of 123659 is 956321.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 956321 = 163 ⋅5867.

It is a cyclic number.

It is not a de Polignac number, because 123659 - 2¹² = 119563 is a prime.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 123659.

It is not an unprimeable number, because it can be changed into a prime (123653) 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, 1964 + ... + 2025.

It is an arithmetic number, because the mean of its divisors is an integer number (31920).

2¹²³⁶⁵⁹ is an apocalyptic number.

123659 is a deficient number, since it is larger than the sum of its proper divisors (4021).

123659 is an equidigital number, since it uses as much as digits as its factorization.

123659 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4020.

The product of its digits is 1620, while the sum is 26.

The square root of 123659 is about 351.6518164321. The cubic root of 123659 is about 49.8205567730.

The spelling of 123659 in words is "one hundred twenty-three thousand, six hundred fifty-nine".