78686528 has 42 divisors (see below), whose sum is σ = 158947866. Its totient is φ = 38648064.

The previous prime is 78686527. The next prime is 78686537. The reversal of 78686528 is 82568687.

It can be written as a sum of positive squares in only one way, i.e., 78287104 + 399424 = 8848^2 + 632^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78686521) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 399326 + ... + 399522.

It is an arithmetic number, because the mean of its divisors is an integer number (3784473).

Almost surely, 2^78686528 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 78686528, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (79473933).

78686528 is an abundant number, since it is smaller than the sum of its proper divisors (80261338).

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

78686528 is an equidigital number, since it uses as much as digits as its factorization.

78686528 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 367 (or 278 counting only the distinct ones).

The product of its digits is 1290240, while the sum is 50.

The square root of 78686528 is about 8870.5427116947. The cubic root of 78686528 is about 428.5157552231.

The spelling of 78686528 in words is "seventy-eight million, six hundred eighty-six thousand, five hundred twenty-eight".