123129905 has 8 divisors (see below), whose sum is σ = 147902784. Its totient is φ = 98406000.

The previous prime is 123129901. The next prime is 123129907. The reversal of 123129905 is 509921321.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 123129905 - 2² = 123129901 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (123129901) 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 7 ways as a sum of consecutive naturals, for example, 6461 + ... + 16970.

It is an arithmetic number, because the mean of its divisors is an integer number (18487848).

Almost surely, 2^123129905 is an apocalyptic number.

It is an amenable number.

123129905 is a deficient number, since it is larger than the sum of its proper divisors (24772879).

123129905 is a wasteful number, since it uses less digits than its factorization.

123129905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24487.

The product of its (nonzero) digits is 4860, while the sum is 32.

The square root of 123129905 is about 11096.3915305833. The cubic root of 123129905 is about 497.4940009209.

The spelling of 123129905 in words is "one hundred twenty-three million, one hundred twenty-nine thousand, nine hundred five".