668497 has 4 divisors (see below), whose sum is σ = 674740. Its totient is φ = 662256.

The previous prime is 668471. The next prime is 668509. The reversal of 668497 is 794866.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 794866 = 2 ⋅397433.

It can be written as a sum of positive squares in 2 ways, for example, as 576081 + 92416 = 759^2 + 304^2 .

It is a cyclic number.

It is not a de Polignac number, because 668497 - 2¹⁵ = 635729 is a prime.

It is a Duffinian number.

668497 is a lucky number.

It is a plaindrome in base 14.

It is not an unprimeable number, because it can be changed into a prime (668407) 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, 2958 + ... + 3175.

It is an arithmetic number, because the mean of its divisors is an integer number (168685).

2⁶⁶⁸⁴⁹⁷ is an apocalyptic number.

It is an amenable number.

668497 is a deficient number, since it is larger than the sum of its proper divisors (6243).

668497 is a wasteful number, since it uses less digits than its factorization.

668497 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6242.

The product of its digits is 72576, while the sum is 40.

The square root of 668497 is about 817.6166583430. The cubic root of 668497 is about 87.4379205922.

The spelling of 668497 in words is "six hundred sixty-eight thousand, four hundred ninety-seven".