668634 has 8 divisors (see below), whose sum is σ = 1337280. Its totient is φ = 222876.

The previous prime is 668623. The next prime is 668671. The reversal of 668634 is 436866.

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

668634 is an admirable number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 668595 and 668604.

It is an unprimeable number.

668634 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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 3 ways as a sum of consecutive naturals, for example, 55714 + ... + 55725.

It is an arithmetic number, because the mean of its divisors is an integer number (167160).

2⁶⁶⁸⁶³⁴ is an apocalyptic number.

668634 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.

668634 is a wasteful number, since it uses less digits than its factorization.

668634 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111444.

The product of its digits is 20736, while the sum is 33.

The square root of 668634 is about 817.7004341444. The cubic root of 668634 is about 87.4438932827.

The spelling of 668634 in words is "six hundred sixty-eight thousand, six hundred thirty-four".