667808 has 24 divisors (see below), whose sum is σ = 1349460. Its totient is φ = 325120.

The previous prime is 667801. The next prime is 667817. The reversal of 667808 is 808766.

It can be written as a sum of positive squares in 2 ways, for example, as 659344 + 8464 = 812^2 + 92^2 .

It is not an unprimeable number, because it can be changed into a prime (667801) by changing a digit.

667808 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 3 ways as a sum of consecutive naturals, for example, 1058 + ... + 1566.

2⁶⁶⁷⁸⁰⁸ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 667808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (674730).

667808 is an abundant number, since it is smaller than the sum of its proper divisors (681652).

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

667808 is a wasteful number, since it uses less digits than its factorization.

667808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 560 (or 552 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 35.

The square root of 667808 is about 817.1952031186. The cubic root of 667808 is about 87.4078703768.

The spelling of 667808 in words is "six hundred sixty-seven thousand, eight hundred eight".