123208905 has 16 divisors (see below), whose sum is σ = 198555840. Its totient is φ = 65237568.

The previous prime is 123208879. The next prime is 123208919. The reversal of 123208905 is 509802321.

It is a happy number.

It is not a de Polignac number, because 123208905 - 2⁷ = 123208777 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27462 + ... + 31631.

It is an arithmetic number, because the mean of its divisors is an integer number (12409740).

Almost surely, 2^123208905 is an apocalyptic number.

123208905 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

123208905 is a deficient number, since it is larger than the sum of its proper divisors (75346935).

123208905 is a wasteful number, since it uses less digits than its factorization.

123208905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59240.

The product of its (nonzero) digits is 4320, while the sum is 30.

The square root of 123208905 is about 11099.9506755661. The cubic root of 123208905 is about 497.6003753599.

The spelling of 123208905 in words is "one hundred twenty-three million, two hundred eight thousand, nine hundred five".