1688138618 has 16 divisors (see below), whose sum is σ = 2557694880. Its totient is φ = 835616016.

The previous prime is 1688138611. The next prime is 1688138623. The reversal of 1688138618 is 8168318861.

It is not an unprimeable number, because it can be changed into a prime (1688138611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 70880 + ... + 91652.

It is an arithmetic number, because the mean of its divisors is an integer number (159855930).

Almost surely, 2^1688138618 is an apocalyptic number.

1688138618 is a deficient number, since it is larger than the sum of its proper divisors (869556262).

1688138618 is a wasteful number, since it uses less digits than its factorization.

1688138618 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21181.

The product of its digits is 442368, while the sum is 50.

The square root of 1688138618 is about 41086.9640883821. The cubic root of 1688138618 is about 1190.7009541660.

The spelling of 1688138618 in words is "one billion, six hundred eighty-eight million, one hundred thirty-eight thousand, six hundred eighteen".