678216 has 64 divisors (see below), whose sum is σ = 2119680. Its totient is φ = 175680.

The previous prime is 678211. The next prime is 678217. The reversal of 678216 is 612876.

It is a happy number.

It is a super-4 number, since 4×678216⁴ (a number of 24 digits) contains 4444 as substring.

It is a hoax number, since the sum of its digits (30) coincides with the sum of the digits of its distinct prime factors.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (678211) by changing a digit.

678216 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1665 + ... + 2031.

It is an arithmetic number, because the mean of its divisors is an integer number (33120).

2⁶⁷⁸²¹⁶ is an apocalyptic number.

678216 is a gapful number since it is divisible by the number (66) 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 678216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1059840).

678216 is an abundant number, since it is smaller than the sum of its proper divisors (1441464).

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

678216 is a wasteful number, since it uses less digits than its factorization.

678216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 394 (or 390 counting only the distinct ones).

The product of its digits is 4032, while the sum is 30.

The square root of 678216 is about 823.5387058299. The cubic root of 678216 is about 87.8596246808.

The spelling of 678216 in words is "six hundred seventy-eight thousand, two hundred sixteen".