678780 has 60 divisors (see below), whose sum is σ = 2134440. Its totient is φ = 180576.

The previous prime is 678779. The next prime is 678809. The reversal of 678780 is 87876.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (60).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 1411 + ... + 1829.

It is an arithmetic number, because the mean of its divisors is an integer number (35574).

2⁶⁷⁸⁷⁸⁰ is an apocalyptic number.

678780 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 678780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1067220).

678780 is an abundant number, since it is smaller than the sum of its proper divisors (1455660).

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

678780 is a wasteful number, since it uses less digits than its factorization.

678780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 440 (or 429 counting only the distinct ones).

The product of its (nonzero) digits is 18816, while the sum is 36.

The square root of 678780 is about 823.8810593769. The cubic root of 678780 is about 87.8839724298.

The spelling of 678780 in words is "six hundred seventy-eight thousand, seven hundred eighty".