668213 has 12 divisors (see below), whose sum is σ = 837900. Its totient is φ = 528192.

The previous prime is 668209. The next prime is 668221. The reversal of 668213 is 312866.

It can be written as a sum of positive squares in 2 ways, for example, as 362404 + 305809 = 602^2 + 553^2 .

It is not a de Polignac number, because 668213 - 2² = 668209 is a prime.

It is a super-2 number, since 2×668213² = 893017226738, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668203) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 113 + ... + 1161.

It is an arithmetic number, because the mean of its divisors is an integer number (69825).

2⁶⁶⁸²¹³ is an apocalyptic number.

It is an amenable number.

668213 is a deficient number, since it is larger than the sum of its proper divisors (169687).

668213 is a wasteful number, since it uses less digits than its factorization.

668213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1076 (or 1069 counting only the distinct ones).

The product of its digits is 1728, while the sum is 26.

The square root of 668213 is about 817.4429643712. The cubic root of 668213 is about 87.4255366489.

The spelling of 668213 in words is "six hundred sixty-eight thousand, two hundred thirteen".