668197 has 4 divisors (see below), whose sum is σ = 669856. Its totient is φ = 666540.

The previous prime is 668179. The next prime is 668201. The reversal of 668197 is 791866.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 668197 - 2⁷ = 668069 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (660197) 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, 208 + ... + 1174.

It is an arithmetic number, because the mean of its divisors is an integer number (167464).

2⁶⁶⁸¹⁹⁷ is an apocalyptic number.

It is an amenable number.

668197 is a deficient number, since it is larger than the sum of its proper divisors (1659).

668197 is an equidigital number, since it uses as much as digits as its factorization.

668197 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1658.

The product of its digits is 18144, while the sum is 37.

The square root of 668197 is about 817.4331776971. The cubic root of 668197 is about 87.4248388576.

The spelling of 668197 in words is "six hundred sixty-eight thousand, one hundred ninety-seven".