138918042 has 24 divisors (see below), whose sum is σ = 301270944. Its totient is φ = 46262664.

The previous prime is 138917981. The next prime is 138918049. The reversal of 138918042 is 240819831.

It is a super-2 number, since 2×138918042² = 38596444786227528, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 138917988 and 138918006.

It is not an unprimeable number, because it can be changed into a prime (138918049) 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 11 ways as a sum of consecutive naturals, for example, 20493 + ... + 26415.

It is an arithmetic number, because the mean of its divisors is an integer number (12552956).

Almost surely, 2^138918042 is an apocalyptic number.

138918042 is an abundant number, since it is smaller than the sum of its proper divisors (162352902).

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

138918042 is a wasteful number, since it uses less digits than its factorization.

138918042 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7234 (or 7231 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The square root of 138918042 is about 11786.3498166311. The cubic root of 138918042 is about 517.9083159885.

The spelling of 138918042 in words is "one hundred thirty-eight million, nine hundred eighteen thousand, forty-two".