123643605 has 32 divisors (see below), whose sum is σ = 204019200. Its totient is φ = 63908352.

The previous prime is 123643571. The next prime is 123643613. The reversal of 123643605 is 506346321.

It is not a de Polignac number, because 123643605 - 2⁷ = 123643477 is a prime.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 76041 + ... + 77649.

It is an arithmetic number, because the mean of its divisors is an integer number (6375600).

Almost surely, 2^123643605 is an apocalyptic number.

123643605 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

123643605 is a deficient number, since it is larger than the sum of its proper divisors (80375595).

123643605 is a wasteful number, since it uses less digits than its factorization.

123643605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1773.

The product of its (nonzero) digits is 12960, while the sum is 30.

The square root of 123643605 is about 11119.5146027154. The cubic root of 123643605 is about 498.1848920732.

Adding to 123643605 its reverse (506346321), we get a palindrome (629989926).

The spelling of 123643605 in words is "one hundred twenty-three million, six hundred forty-three thousand, six hundred five".