7878 has 16 divisors (see below), whose sum is σ = 17136. Its totient is φ = 2400.

The previous prime is 7877. The next prime is 7879. The reversal of 7878 is 8787.

It is a happy number.

7878 is an esthetic number in base 10, because in such base its adjacent digits differ by 1.

It is an interprime number because it is at equal distance from previous prime (7877) and next prime (7879).

It is an alternating number because its digits alternate between odd and even.

7878 is an undulating number in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7873) 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, 28 + ... + 128.

It is an arithmetic number, because the mean of its divisors is an integer number (1071).

2⁷⁸⁷⁸ is an apocalyptic number.

7878 is a gapful number since it is divisible by the number (78) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 7878, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8568).

7878 is an abundant number, since it is smaller than the sum of its proper divisors (9258).

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

7878 is a wasteful number, since it uses less digits than its factorization.

7878 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 119.

The product of its digits is 3136, while the sum is 30.

The square root of 7878 is about 88.7580982221. The cubic root of 7878 is about 19.8978121043.

Subtracting 7878 from its reverse (8787), we obtain a palindrome (909).

The spelling of 7878 in words is "seven thousand, eight hundred seventy-eight".