405678 has 32 divisors (see below), whose sum is σ = 999936. Its totient is φ = 106848.

The previous prime is 405677. The next prime is 405679. The reversal of 405678 is 876504.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (405677) and next prime (405679).

It is a Smith number, since the sum of its digits (30) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (405677) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 175 + ... + 917.

It is an arithmetic number, because the mean of its divisors is an integer number (31248).

2⁴⁰⁵⁶⁷⁸ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 405678, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (499968).

405678 is an abundant number, since it is smaller than the sum of its proper divisors (594258).

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

405678 is a wasteful number, since it uses less digits than its factorization.

405678 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 768.

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

The square root of 405678 is about 636.9285674234. The cubic root of 405678 is about 74.0276254295.

The spelling of 405678 in words is "four hundred five thousand, six hundred seventy-eight".