123138506 has 16 divisors (see below), whose sum is σ = 194715360. Its totient is φ = 58242960.

The previous prime is 123138503. The next prime is 123138511. The reversal of 123138506 is 605831321.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (123138503) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 29225 + ... + 33171.

It is an arithmetic number, because the mean of its divisors is an integer number (12169710).

Almost surely, 2^123138506 is an apocalyptic number.

123138506 is a deficient number, since it is larger than the sum of its proper divisors (71576854).

123138506 is a wasteful number, since it uses less digits than its factorization.

123138506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4789.

The product of its (nonzero) digits is 4320, while the sum is 29.

The square root of 123138506 is about 11096.7790822382. The cubic root of 123138506 is about 497.5055844764.

Adding to 123138506 its reverse (605831321), we get a palindrome (728969827).

The spelling of 123138506 in words is "one hundred twenty-three million, one hundred thirty-eight thousand, five hundred six".