668942 has 8 divisors (see below), whose sum is σ = 1020600. Its totient is φ = 328744.

The previous prime is 668939. The next prime is 668947. The reversal of 668942 is 249866.

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

It is a super-4 number, since 4×668942⁴ (a number of 24 digits) contains 4444 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668947) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2717 + ... + 2952.

It is an arithmetic number, because the mean of its divisors is an integer number (127575).

2⁶⁶⁸⁹⁴² is an apocalyptic number.

668942 is a deficient number, since it is larger than the sum of its proper divisors (351658).

668942 is a wasteful number, since it uses less digits than its factorization.

668942 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5730.

The product of its digits is 20736, while the sum is 35.

The square root of 668942 is about 817.8887454905. Note that the first 3 decimals coincide. The cubic root of 668942 is about 87.4573179588.

The spelling of 668942 in words is "six hundred sixty-eight thousand, nine hundred forty-two".