668365 has 4 divisors (see below), whose sum is σ = 802044. Its totient is φ = 534688.

The previous prime is 668347. The next prime is 668407. The reversal of 668365 is 563866.

668365 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 563866 = 2 ⋅281933.

It can be written as a sum of positive squares in 2 ways, for example, as 175561 + 492804 = 419^2 + 702^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-668365 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 668365.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 66832 + ... + 66841.

It is an arithmetic number, because the mean of its divisors is an integer number (200511).

2⁶⁶⁸³⁶⁵ is an apocalyptic number.

It is an amenable number.

668365 is a deficient number, since it is larger than the sum of its proper divisors (133679).

668365 is a wasteful number, since it uses less digits than its factorization.

668365 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133678.

The product of its digits is 25920, while the sum is 34.

The square root of 668365 is about 817.5359319320. The cubic root of 668365 is about 87.4321651113.

The spelling of 668365 in words is "six hundred sixty-eight thousand, three hundred sixty-five".