138206618 has 32 divisors (see below), whose sum is σ = 239804928. Its totient is φ = 59140800.

The previous prime is 138206603. The next prime is 138206623. The reversal of 138206618 is 816602831.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22496 + ... + 27972.

It is an arithmetic number, because the mean of its divisors is an integer number (7493904).

Almost surely, 2^138206618 is an apocalyptic number.

138206618 is a deficient number, since it is larger than the sum of its proper divisors (101598310).

138206618 is a wasteful number, since it uses less digits than its factorization.

138206618 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5558.

The product of its (nonzero) digits is 13824, while the sum is 35.

The square root of 138206618 is about 11756.1310812699. The cubic root of 138206618 is about 517.0227022693.

The spelling of 138206618 in words is "one hundred thirty-eight million, two hundred six thousand, six hundred eighteen".