78117215904 has 864 divisors, whose sum is σ = 297919702080. Its totient is φ = 19187933184.

The previous prime is 78117215851. The next prime is 78117215941. The reversal of 78117215904 is 40951271187.

It is a happy number.

It is a super-2 number, since 2×78117215904² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 78117215904.

It is an unprimeable number.

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 143 ways as a sum of consecutive naturals, for example, 254453319 + ... + 254453625.

It is an arithmetic number, because the mean of its divisors is an integer number (344814470).

Almost surely, 2^78117215904 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 78117215904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (148959851040).

78117215904 is an abundant number, since it is smaller than the sum of its proper divisors (219802486176).

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

78117215904 is a wasteful number, since it uses less digits than its factorization.

78117215904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 442 (or 424 counting only the distinct ones).

The product of its (nonzero) digits is 141120, while the sum is 45.

The spelling of 78117215904 in words is "seventy-eight billion, one hundred seventeen million, two hundred fifteen thousand, nine hundred four".