668245 has 4 divisors (see below), whose sum is σ = 801900. Its totient is φ = 534592.

The previous prime is 668243. The next prime is 668273. The reversal of 668245 is 542866.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 69169 + 599076 = 263^2 + 774^2 .

It is a cyclic number.

It is not a de Polignac number, because 668245 - 2¹ = 668243 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668243) 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, 66820 + ... + 66829.

It is an arithmetic number, because the mean of its divisors is an integer number (200475).

2⁶⁶⁸²⁴⁵ is an apocalyptic number.

It is an amenable number.

668245 is a deficient number, since it is larger than the sum of its proper divisors (133655).

668245 is a wasteful number, since it uses less digits than its factorization.

668245 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133654.

The product of its digits is 11520, while the sum is 31.

The square root of 668245 is about 817.4625373679. The cubic root of 668245 is about 87.4269321982.

The spelling of 668245 in words is "six hundred sixty-eight thousand, two hundred forty-five".