667578 has 8 divisors (see below), whose sum is σ = 1335168. Its totient is φ = 222524.

The previous prime is 667577. The next prime is 667631. The reversal of 667578 is 875766.

It is a sphenic number, since it is the product of 3 distinct primes.

667578 is an admirable number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (667577) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 55626 + ... + 55637.

It is an arithmetic number, because the mean of its divisors is an integer number (166896).

2⁶⁶⁷⁵⁷⁸ is an apocalyptic number.

667578 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

667578 is a wasteful number, since it uses less digits than its factorization.

667578 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111268.

The product of its digits is 70560, while the sum is 39.

The square root of 667578 is about 817.0544657488. The cubic root of 667578 is about 87.3978344989.

The spelling of 667578 in words is "six hundred sixty-seven thousand, five hundred seventy-eight".