678405 has 48 divisors (see below), whose sum is σ = 1378944. Its totient is φ = 282240.

The previous prime is 678401. The next prime is 678407. The reversal of 678405 is 504876.

It is a happy number.

It is not a de Polignac number, because 678405 - 2² = 678401 is a prime.

It is a Curzon number.

It is a zygodrome in base 4.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (678401) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 9520 + ... + 9590.

It is an arithmetic number, because the mean of its divisors is an integer number (28728).

2⁶⁷⁸⁴⁰⁵ is an apocalyptic number.

678405 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

678405 is an abundant number, since it is smaller than the sum of its proper divisors (700539).

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

678405 is a wasteful number, since it uses less digits than its factorization.

678405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106 (or 99 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 30.

The square root of 678405 is about 823.6534465417. The cubic root of 678405 is about 87.8677852702.

The spelling of 678405 in words is "six hundred seventy-eight thousand, four hundred five".