78084 has 30 divisors (see below), whose sum is σ = 204974. Its totient is φ = 25920.

The previous prime is 78079. The next prime is 78101. The reversal of 78084 is 48087.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 72900 + 5184 = 270^2 + 72^2 .

It is a super-2 number, since 2×78084² = 12194222112, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 204 + ... + 444.

2⁷⁸⁰⁸⁴ 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 78084, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (102487).

78084 is an abundant number, since it is smaller than the sum of its proper divisors (126890).

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

78084 is a wasteful number, since it uses less digits than its factorization.

78084 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 257 (or 246 counting only the distinct ones).

The product of its (nonzero) digits is 1792, while the sum is 27.

The square root of 78084 is about 279.4351445327. The cubic root of 78084 is about 42.7419190635.

The spelling of 78084 in words is "seventy-eight thousand, eighty-four".