123809556 has 48 divisors (see below), whose sum is σ = 318363584. Its totient is φ = 37207296.

The previous prime is 123809551. The next prime is 123809579. The reversal of 123809556 is 655908321.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123809551) 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 15 ways as a sum of consecutive naturals, for example, 2521 + ... + 15936.

Almost surely, 2^123809556 is an apocalyptic number.

It is an amenable number.

123809556 is an abundant number, since it is smaller than the sum of its proper divisors (194554028).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

123809556 is a wasteful number, since it uses less digits than its factorization.

123809556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18520 (or 18518 counting only the distinct ones).

The product of its (nonzero) digits is 64800, while the sum is 39.

The square root of 123809556 is about 11126.9742517901. The cubic root of 123809556 is about 498.4076757232.

The spelling of 123809556 in words is "one hundred twenty-three million, eight hundred nine thousand, five hundred fifty-six".