668494 has 4 divisors (see below), whose sum is σ = 1002744. Its totient is φ = 334246.

The previous prime is 668471. The next prime is 668509. The reversal of 668494 is 494866.

668494 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 494866 = 2 ⋅247433.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 167122 + ... + 167125.

It is an arithmetic number, because the mean of its divisors is an integer number (250686).

2⁶⁶⁸⁴⁹⁴ is an apocalyptic number.

668494 is a deficient number, since it is larger than the sum of its proper divisors (334250).

668494 is a wasteful number, since it uses less digits than its factorization.

668494 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 334249.

The product of its digits is 41472, while the sum is 37.

The square root of 668494 is about 817.6148237404. The cubic root of 668494 is about 87.4377897943.

The spelling of 668494 in words is "six hundred sixty-eight thousand, four hundred ninety-four".