123919509 has 16 divisors (see below), whose sum is σ = 190085120. Its totient is φ = 70340400.

The previous prime is 123919447. The next prime is 123919513. The reversal of 123919509 is 905919321.

It is not a de Polignac number, because 123919509 - 2²⁰ = 122870933 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123919519) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16369 + ... + 22710.

It is an arithmetic number, because the mean of its divisors is an integer number (11880320).

Almost surely, 2^123919509 is an apocalyptic number.

It is an amenable number.

123919509 is a deficient number, since it is larger than the sum of its proper divisors (66165611).

123919509 is a wasteful number, since it uses less digits than its factorization.

123919509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39240.

The product of its (nonzero) digits is 21870, while the sum is 39.

The square root of 123919509 is about 11131.9139863727. The cubic root of 123919509 is about 498.5551743123. Note that the first 3 decimals are identical.

The spelling of 123919509 in words is "one hundred twenty-three million, nine hundred nineteen thousand, five hundred nine".