123609505 has 8 divisors (see below), whose sum is σ = 148400424. Its totient is φ = 98841600.

The previous prime is 123609491. The next prime is 123609511. The reversal of 123609505 is 505906321.

It can be written as a sum of positive squares in 4 ways, for example, as 221841 + 123387664 = 471^2 + 11108^2 .

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

It is not a de Polignac number, because 123609505 - 2⁹ = 123608993 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9985 + ... + 18625.

It is an arithmetic number, because the mean of its divisors is an integer number (18550053).

Almost surely, 2^123609505 is an apocalyptic number.

It is an amenable number.

123609505 is a deficient number, since it is larger than the sum of its proper divisors (24790919).

123609505 is an equidigital number, since it uses as much as digits as its factorization.

123609505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11507.

The product of its (nonzero) digits is 8100, while the sum is 31.

The square root of 123609505 is about 11117.9811566669. The cubic root of 123609505 is about 498.1390892817.

The spelling of 123609505 in words is "one hundred twenty-three million, six hundred nine thousand, five hundred five".