123689 has 4 divisors (see below), whose sum is σ = 124560. Its totient is φ = 122820.

The previous prime is 123677. The next prime is 123701. The reversal of 123689 is 986321.

123689 is nontrivially palindromic in base 12.

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 an interprime number because it is at equal distance from previous prime (123677) and next prime (123701).

It is a cyclic number.

It is not a de Polignac number, because 123689 - 2⁸ = 123433 is a prime.

It is a Duffinian number.

It is a plaindrome in base 10 and base 15.

It is not an unprimeable number, because it can be changed into a prime (123619) 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, 167 + ... + 524.

It is an arithmetic number, because the mean of its divisors is an integer number (31140).

2¹²³⁶⁸⁹ is an apocalyptic number.

It is an amenable number.

123689 is a deficient number, since it is larger than the sum of its proper divisors (871).

123689 is an equidigital number, since it uses as much as digits as its factorization.

123689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 870.

The product of its digits is 2592, while the sum is 29.

The square root of 123689 is about 351.6944696750. The cubic root of 123689 is about 49.8245853134.

The spelling of 123689 in words is "one hundred twenty-three thousand, six hundred eighty-nine".