642015678618 has 48 divisors (see below), whose sum is σ = 1491503345280. Its totient is φ = 198867097728.

The previous prime is 642015678607. The next prime is 642015678641. The reversal of 642015678618 is 816876510246.

642015678618 is a `hidden beast` number, since 6 + 4 + 2 + 0 + 15 + 6 + 7 + 8 + 618 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 13254880 + ... + 13303227.

It is an arithmetic number, because the mean of its divisors is an integer number (31072986360).

Almost surely, 2^642015678618 is an apocalyptic number.

642015678618 is an abundant number, since it is smaller than the sum of its proper divisors (849487666662).

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

642015678618 is a wasteful number, since it uses less digits than its factorization.

642015678618 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26558211 (or 26558208 counting only the distinct ones).

The product of its (nonzero) digits is 3870720, while the sum is 54.

The spelling of 642015678618 in words is "six hundred forty-two billion, fifteen million, six hundred seventy-eight thousand, six hundred eighteen".