123309 has 8 divisors (see below), whose sum is σ = 182720. Its totient is φ = 82188.

The previous prime is 123307. The next prime is 123311. The reversal of 123309 is 903321.

It is an interprime number because it is at equal distance from previous prime (123307) and next prime (123311).

It is not a de Polignac number, because 123309 - 2¹ = 123307 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 123291 and 123300.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123307) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2257 + ... + 2310.

It is an arithmetic number, because the mean of its divisors is an integer number (22840).

2¹²³³⁰⁹ is an apocalyptic number.

It is an amenable number.

123309 is a deficient number, since it is larger than the sum of its proper divisors (59411).

123309 is an equidigital number, since it uses as much as digits as its factorization.

123309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4576 (or 4570 counting only the distinct ones).

The product of its (nonzero) digits is 162, while the sum is 18.

The square root of 123309 is about 351.1538124526. The cubic root of 123309 is about 49.7735089183.

It can be divided in two parts, 12 and 3309, that added together give a triangular number (3321 = T₈₁).

The spelling of 123309 in words is "one hundred twenty-three thousand, three hundred nine".