138556218 has 16 divisors (see below), whose sum is σ = 279804096. Its totient is φ = 45736800.

The previous prime is 138556217. The next prime is 138556237. The reversal of 138556218 is 812655831.

It is not an unprimeable number, because it can be changed into a prime (138556217) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 111483 + ... + 112718.

It is an arithmetic number, because the mean of its divisors is an integer number (17487756).

Almost surely, 2^138556218 is an apocalyptic number.

138556218 is an abundant number, since it is smaller than the sum of its proper divisors (141247878).

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

138556218 is a wasteful number, since it uses less digits than its factorization.

138556218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 224309.

The product of its digits is 57600, while the sum is 39.

The square root of 138556218 is about 11770.9905275639. The cubic root of 138556218 is about 517.4582794437.

The spelling of 138556218 in words is "one hundred thirty-eight million, five hundred fifty-six thousand, two hundred eighteen".