78438591936 has 168 divisors, whose sum is σ = 237300211200. Its totient is φ = 24703418880.

The previous prime is 78438591919. The next prime is 78438591961. The reversal of 78438591936 is 63919583487.

78438591936 is a `hidden beast` number, since 7 + 8 + 4 + 3 + 8 + 591 + 9 + 36 = 666.

It is a super-2 number, since 2×78438591936² (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 (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4138321 + ... + 4157231.

Almost surely, 2^78438591936 is an apocalyptic number.

78438591936 is a gapful number since it is divisible by the number (76) 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 78438591936, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (118650105600).

78438591936 is an abundant number, since it is smaller than the sum of its proper divisors (158861619264).

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

78438591936 is a wasteful number, since it uses less digits than its factorization.

78438591936 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19327 (or 19314 counting only the distinct ones).

The product of its digits is 39191040, while the sum is 63.

The spelling of 78438591936 in words is "seventy-eight billion, four hundred thirty-eight million, five hundred ninety-one thousand, nine hundred thirty-six".