123509505 has 32 divisors (see below), whose sum is σ = 239134464. Its totient is φ = 53139456.

The previous prime is 123509497. The next prime is 123509509. The reversal of 123509505 is 505905321.

It is not a de Polignac number, because 123509505 - 2³ = 123509497 is a prime.

It is not an unprimeable number, because it can be changed into a prime (123509509) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 32812 + ... + 36381.

It is an arithmetic number, because the mean of its divisors is an integer number (7472952).

Almost surely, 2^123509505 is an apocalyptic number.

123509505 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

123509505 is a deficient number, since it is larger than the sum of its proper divisors (115624959).

123509505 is a wasteful number, since it uses less digits than its factorization.

123509505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69225.

The product of its (nonzero) digits is 6750, while the sum is 30.

The square root of 123509505 is about 11113.4830273861. The cubic root of 123509505 is about 498.0047216533.

The spelling of 123509505 in words is "one hundred twenty-three million, five hundred nine thousand, five hundred five".