668428 has 6 divisors (see below), whose sum is σ = 1169756. Its totient is φ = 334212.

The previous prime is 668417. The next prime is 668471. The reversal of 668428 is 824866.

It is a junction number, because it is equal to n+sod(n) for n = 668393 and 668402.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83550 + ... + 83557.

2⁶⁶⁸⁴²⁸ is an apocalyptic number.

It is an amenable number.

668428 is a deficient number, since it is larger than the sum of its proper divisors (501328).

668428 is a wasteful number, since it uses less digits than its factorization.

668428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167111 (or 167109 counting only the distinct ones).

The product of its digits is 18432, while the sum is 34.

The square root of 668428 is about 817.5744614407. The cubic root of 668428 is about 87.4349121399.

The spelling of 668428 in words is "six hundred sixty-eight thousand, four hundred twenty-eight".