78505716520 has 256 divisors, whose sum is σ = 225358848000. Its totient is φ = 24399648000.

The previous prime is 78505716511. The next prime is 78505716557. The reversal of 78505716520 is 2561750587.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 86174865 + ... + 86175775.

It is an arithmetic number, because the mean of its divisors is an integer number (880308000).

Almost surely, 2^78505716520 is an apocalyptic number.

78505716520 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 78505716520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (112679424000).

78505716520 is an abundant number, since it is smaller than the sum of its proper divisors (146853131480).

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

78505716520 is a wasteful number, since it uses less digits than its factorization.

78505716520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1525 (or 1507 counting only the distinct ones).

The product of its (nonzero) digits is 588000, while the sum is 46.

The spelling of 78505716520 in words is "seventy-eight billion, five hundred five million, seven hundred sixteen thousand, five hundred twenty".