678776 has 64 divisors (see below), whose sum is σ = 1658880. Its totient is φ = 253440.

The previous prime is 678773. The next prime is 678779. The reversal of 678776 is 677876.

It is an interprime number because it is at equal distance from previous prime (678773) and next prime (678779).

Its product of digits (98784) is a multiple of the sum of its prime factors (84).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (678773) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 21881 + ... + 21911.

It is an arithmetic number, because the mean of its divisors is an integer number (25920).

2⁶⁷⁸⁷⁷⁶ is an apocalyptic number.

678776 is the 476-th octagonal number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 678776, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (829440).

678776 is an abundant number, since it is smaller than the sum of its proper divisors (980104).

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

678776 is a wasteful number, since it uses less digits than its factorization.

678776 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84 (or 80 counting only the distinct ones).

The product of its digits is 98784, while the sum is 41.

The square root of 678776 is about 823.8786318385. The cubic root of 678776 is about 87.8837997982.

Subtracting from 678776 its reverse (677876), we obtain a square (900 = 30²).

The spelling of 678776 in words is "six hundred seventy-eight thousand, seven hundred seventy-six".