669878 has 8 divisors (see below), whose sum is σ = 1096200. Its totient is φ = 304480.

The previous prime is 669869. The next prime is 669887. The reversal of 669878 is 878966.

669878 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (669869) and next prime (669887).

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

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 669878.

It is an unprimeable number.

669878 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, 15203 + ... + 15246.

It is an arithmetic number, because the mean of its divisors is an integer number (137025).

2⁶⁶⁹⁸⁷⁸ is an apocalyptic number.

669878 is a deficient number, since it is larger than the sum of its proper divisors (426322).

669878 is a wasteful number, since it uses less digits than its factorization.

669878 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30462.

The product of its digits is 145152, while the sum is 44.

The square root of 669878 is about 818.4607504334. The cubic root of 669878 is about 87.4980897542.

It can be divided in two parts, 6698 and 78, that added together give a palindrome (6776).

The spelling of 669878 in words is "six hundred sixty-nine thousand, eight hundred seventy-eight".