78318121840 has 160 divisors (see below), whose sum is σ = 209609012736. Its totient is φ = 26658339840.

The previous prime is 78318121789. The next prime is 78318121873. The reversal of 78318121840 is 4812181387.

It is a super-2 number, since 2×78318121840² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 52456134 + ... + 52457626.

Almost surely, 2^78318121840 is an apocalyptic number.

78318121840 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 78318121840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (104804506368).

78318121840 is an abundant number, since it is smaller than the sum of its proper divisors (131290890896).

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

78318121840 is a wasteful number, since it uses less digits than its factorization.

78318121840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2127 (or 2121 counting only the distinct ones).

The product of its (nonzero) digits is 86016, while the sum is 43.

The spelling of 78318121840 in words is "seventy-eight billion, three hundred eighteen million, one hundred twenty-one thousand, eight hundred forty".