123705609 has 4 divisors (see below), whose sum is σ = 164940816. Its totient is φ = 82470404.

The previous prime is 123705557. The next prime is 123705613. The reversal of 123705609 is 906507321.

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 an emirpimes, since its reverse is a distinct semiprime: 906507321 = 3 ⋅302169107.

It is a cyclic number.

It is not a de Polignac number, because 123705609 - 2⁸ = 123705353 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 123705609.

It is not an unprimeable number, because it can be changed into a prime (123705629) 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, 20617599 + ... + 20617604.

It is an arithmetic number, because the mean of its divisors is an integer number (41235204).

Almost surely, 2^123705609 is an apocalyptic number.

It is an amenable number.

123705609 is a deficient number, since it is larger than the sum of its proper divisors (41235207).

123705609 is an equidigital number, since it uses as much as digits as its factorization.

123705609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41235206.

The product of its (nonzero) digits is 11340, while the sum is 33.

The square root of 123705609 is about 11122.3023246089. The cubic root of 123705609 is about 498.2681536757.

The spelling of 123705609 in words is "one hundred twenty-three million, seven hundred five thousand, six hundred nine".