78720 has 64 divisors (see below), whose sum is σ = 257040. Its totient is φ = 20480.

The previous prime is 78713. The next prime is 78721. The reversal of 78720 is 2787.

It is a tau number, because it is divible by the number of its divisors (64).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 78720.

It is not an unprimeable number, because it can be changed into a prime (78721) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1900 + ... + 1940.

2⁷⁸⁷²⁰ 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 78720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (128520).

78720 is an abundant number, since it is smaller than the sum of its proper divisors (178320).

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

78720 is a wasteful number, since it uses less digits than its factorization.

78720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63 (or 51 counting only the distinct ones).

The product of its (nonzero) digits is 784, while the sum is 24.

The square root of 78720 is about 280.5708466680. The cubic root of 78720 is about 42.8576507876.

The spelling of 78720 in words is "seventy-eight thousand, seven hundred twenty".