668519 has 4 divisors (see below), whose sum is σ = 675240. Its totient is φ = 661800.

The previous prime is 668513. The next prime is 668527. The reversal of 668519 is 915866.

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

It is a cyclic number.

It is not a de Polignac number, because 668519 - 2¹⁶ = 602983 is a prime.

It is a super-2 number, since 2×668519² = 893835306722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668513) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3209 + ... + 3410.

It is an arithmetic number, because the mean of its divisors is an integer number (168810).

2⁶⁶⁸⁵¹⁹ is an apocalyptic number.

668519 is a deficient number, since it is larger than the sum of its proper divisors (6721).

668519 is a wasteful number, since it uses less digits than its factorization.

668519 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6720.

The product of its digits is 12960, while the sum is 35.

The square root of 668519 is about 817.6301119700. The cubic root of 668519 is about 87.4388797654.

It can be divided in two parts, 6 and 68519, that multiplied together give a palindrome (411114).

The spelling of 668519 in words is "six hundred sixty-eight thousand, five hundred nineteen".