78173684638140 has 768 divisors, whose sum is σ = 277043948052480. Its totient is φ = 16032584171520.

The previous prime is 78173684638139. The next prime is 78173684638177. The reversal of 78173684638140 is 4183648637187.

It is a super-2 number, since 2×78173684638140² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 255 ways as a sum of consecutive naturals, for example, 29689966264 + ... + 29689968896.

It is an arithmetic number, because the mean of its divisors is an integer number (360734307360).

Almost surely, 2^{78173684638140} is an apocalyptic number.

78173684638140 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 78173684638140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (138521974026240).

78173684638140 is an abundant number, since it is smaller than the sum of its proper divisors (198870263414340).

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

78173684638140 is a wasteful number, since it uses less digits than its factorization.

78173684638140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3742 (or 3740 counting only the distinct ones).

The product of its (nonzero) digits is 130056192, while the sum is 66.

The spelling of 78173684638140 in words is "seventy-eight trillion, one hundred seventy-three billion, six hundred eighty-four million, six hundred thirty-eight thousand, one hundred forty".