668513 has 2 divisors, whose sum is σ = 668514. Its totient is φ = 668512.

The previous prime is 668509. The next prime is 668527. The reversal of 668513 is 315866.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 667489 + 1024 = 817^2 + 32^2 .

It is a cyclic number.

It is not a de Polignac number, because 668513 - 2² = 668509 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a plaindrome in base 14.

It is not a weakly prime, because it can be changed into another prime (668533) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334256 + 334257.

It is an arithmetic number, because the mean of its divisors is an integer number (334257).

2⁶⁶⁸⁵¹³ is an apocalyptic number.

It is an amenable number.

668513 is a deficient number, since it is larger than the sum of its proper divisors (1).

668513 is an equidigital number, since it uses as much as digits as its factorization.

668513 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4320, while the sum is 29.

The square root of 668513 is about 817.6264428209. The cubic root of 668513 is about 87.4386181748.

The spelling of 668513 in words is "six hundred sixty-eight thousand, five hundred thirteen".