78521386680 has 768 divisors, whose sum is σ = 297849277440. Its totient is φ = 17914659840.

The previous prime is 78521386679. The next prime is 78521386681. The reversal of 78521386680 is 8668312587.

78521386680 is a `hidden beast` number, since 7 + 8 + 521 + 38 + 6 + 6 + 80 = 666.

It is an interprime number because it is at equal distance from previous prime (78521386679) and next prime (78521386681).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78521386681) by changing a digit.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 762343509 + ... + 762343611.

It is an arithmetic number, because the mean of its divisors is an integer number (387824580).

Almost surely, 2^78521386680 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 78521386680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (148924638720).

78521386680 is an abundant number, since it is smaller than the sum of its proper divisors (219327890760).

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

78521386680 is a wasteful number, since it uses less digits than its factorization.

78521386680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 233 (or 204 counting only the distinct ones).

The product of its (nonzero) digits is 3870720, while the sum is 54.

The spelling of 78521386680 in words is "seventy-eight billion, five hundred twenty-one million, three hundred eighty-six thousand, six hundred eighty".