78317421618 has 32 divisors (see below), whose sum is σ = 165906728064. Its totient is φ = 24561568512.

The previous prime is 78317421617. The next prime is 78317421649. The reversal of 78317421618 is 81612471387.

It is a super-2 number, since 2×78317421618² (a number of 23 digits) contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (78317421617) 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 15 ways as a sum of consecutive naturals, for example, 161496 + ... + 427452.

It is an arithmetic number, because the mean of its divisors is an integer number (5184585252).

Almost surely, 2^78317421618 is an apocalyptic number.

78317421618 is an abundant number, since it is smaller than the sum of its proper divisors (87589306446).

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

78317421618 is a wasteful number, since it uses less digits than its factorization.

78317421618 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 268866.

The product of its digits is 451584, while the sum is 48.

The spelling of 78317421618 in words is "seventy-eight billion, three hundred seventeen million, four hundred twenty-one thousand, six hundred eighteen".