668478 has 16 divisors (see below), whose sum is σ = 1368576. Its totient is φ = 217560.

The previous prime is 668471. The next prime is 668509. The reversal of 668478 is 874866.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668471) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1038 + ... + 1553.

It is an arithmetic number, because the mean of its divisors is an integer number (85536).

2⁶⁶⁸⁴⁷⁸ is an apocalyptic number.

668478 is an abundant number, since it is smaller than the sum of its proper divisors (700098).

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

668478 is a wasteful number, since it uses less digits than its factorization.

668478 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2639.

The product of its digits is 64512, while the sum is 39.

The square root of 668478 is about 817.6050391234. The cubic root of 668478 is about 87.4370921985.

The spelling of 668478 in words is "six hundred sixty-eight thousand, four hundred seventy-eight".