78439680 has 216 divisors, whose sum is σ = 296543520. Its totient is φ = 18984960.

The previous prime is 78439679. The next prime is 78439681. The reversal of 78439680 is 8693487.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (78439679) and next prime (78439681).

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78439681) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 126411 + ... + 127029.

Almost surely, 2^78439680 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 78439680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (148271760).

78439680 is an abundant number, since it is smaller than the sum of its proper divisors (218103840).

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

78439680 is a wasteful number, since it uses less digits than its factorization.

78439680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 657 (or 640 counting only the distinct ones).

The product of its (nonzero) digits is 290304, while the sum is 45.

The square root of 78439680 is about 8856.6178646253. The cubic root of 78439680 is about 428.0671860056.

The spelling of 78439680 in words is "seventy-eight million, four hundred thirty-nine thousand, six hundred eighty".