78240 has 48 divisors (see below), whose sum is σ = 247968. Its totient is φ = 20736.

The previous prime is 78233. The next prime is 78241. The reversal of 78240 is 4287.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (48).

It is a super-2 number, since 2×78240² = 12242995200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78241) by changing a digit.

78240 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 399 + ... + 561.

It is an arithmetic number, because the mean of its divisors is an integer number (5166).

2⁷⁸²⁴⁰ 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 78240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (123984).

78240 is an abundant number, since it is smaller than the sum of its proper divisors (169728).

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

78240 is a wasteful number, since it uses less digits than its factorization.

78240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 181 (or 173 counting only the distinct ones).

The product of its (nonzero) digits is 448, while the sum is 21.

The square root of 78240 is about 279.7141397928. The cubic root of 78240 is about 42.7703640882.

The spelling of 78240 in words is "seventy-eight thousand, two hundred forty".