668426 has 16 divisors (see below), whose sum is σ = 1142208. Its totient is φ = 290400.

The previous prime is 668417. The next prime is 668471. The reversal of 668426 is 624866.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 668392 and 668401.

It is an unprimeable number.

668426 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 7 ways as a sum of consecutive naturals, for example, 155 + ... + 1166.

It is an arithmetic number, because the mean of its divisors is an integer number (71388).

2⁶⁶⁸⁴²⁶ is an apocalyptic number.

668426 is a deficient number, since it is larger than the sum of its proper divisors (473782).

668426 is a wasteful number, since it uses less digits than its factorization.

668426 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1357.

The product of its digits is 13824, while the sum is 32.

The square root of 668426 is about 817.5732383096. The cubic root of 668426 is about 87.4348249353.

The spelling of 668426 in words is "six hundred sixty-eight thousand, four hundred twenty-six".