123709 has 8 divisors (see below), whose sum is σ = 138240. Its totient is φ = 110016.

The previous prime is 123707. The next prime is 123719. The reversal of 123709 is 907321.

123709 = 22² + 23² + ... + 72².

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

It is a cyclic number.

It is not a de Polignac number, because 123709 - 2¹ = 123707 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 123709.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 132 + ... + 514.

It is an arithmetic number, because the mean of its divisors is an integer number (17280).

2¹²³⁷⁰⁹ is an apocalyptic number.

123709 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

123709 is a deficient number, since it is larger than the sum of its proper divisors (14531).

123709 is a wasteful number, since it uses less digits than its factorization.

123709 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 419.

The product of its (nonzero) digits is 378, while the sum is 22.

The square root of 123709 is about 351.7229022967. The cubic root of 123709 is about 49.8272706452.

It can be divided in two parts, 12 and 3709, that added together give a square (3721 = 61²).

The spelling of 123709 in words is "one hundred twenty-three thousand, seven hundred nine".