669678 has 16 divisors (see below), whose sum is σ = 1347840. Its totient is φ = 221816.

The previous prime is 669677. The next prime is 669679. The reversal of 669678 is 876966.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (669677) and next prime (669679).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (669673) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1201 + ... + 1667.

It is an arithmetic number, because the mean of its divisors is an integer number (84240).

2⁶⁶⁹⁶⁷⁸ is an apocalyptic number.

669678 is an abundant number, since it is smaller than the sum of its proper divisors (678162).

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

669678 is a wasteful number, since it uses less digits than its factorization.

669678 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 711.

The product of its digits is 108864, while the sum is 42.

The square root of 669678 is about 818.3385607437. The cubic root of 669678 is about 87.4893810243.

The spelling of 669678 in words is "six hundred sixty-nine thousand, six hundred seventy-eight".