668894 has 4 divisors (see below), whose sum is σ = 1003344. Its totient is φ = 334446.

The previous prime is 668879. The next prime is 668903. The reversal of 668894 is 498866.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 498866 = 2 ⋅249433.

It is a congruent number.

It is an unprimeable number.

668894 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 as a sum of consecutive naturals, namely, 167222 + ... + 167225.

It is an arithmetic number, because the mean of its divisors is an integer number (250836).

2⁶⁶⁸⁸⁹⁴ is an apocalyptic number.

668894 is a deficient number, since it is larger than the sum of its proper divisors (334450).

668894 is a wasteful number, since it uses less digits than its factorization.

668894 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 334449.

The product of its digits is 82944, while the sum is 41.

The square root of 668894 is about 817.8594011198. The cubic root of 668894 is about 87.4552260726.

The spelling of 668894 in words is "six hundred sixty-eight thousand, eight hundred ninety-four".