668146321 has 4 divisors (see below), whose sum is σ = 669937972. Its totient is φ = 666354672.

The previous prime is 668146309. The next prime is 668146327. The reversal of 668146321 is 123641866.

It is a happy number.

668146321 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.

It can be written as a sum of positive squares in 2 ways, for example, as 204347025 + 463799296 = 14295^2 + 21536^2 .

It is a cyclic number.

It is not a de Polignac number, because 668146321 - 2¹⁵ = 668113553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (668146327) 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, 895266 + ... + 896011.

It is an arithmetic number, because the mean of its divisors is an integer number (167484493).

Almost surely, 2^668146321 is an apocalyptic number.

It is an amenable number.

668146321 is a deficient number, since it is larger than the sum of its proper divisors (1791651).

668146321 is a wasteful number, since it uses less digits than its factorization.

668146321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1791650.

The product of its digits is 41472, while the sum is 37.

The square root of 668146321 is about 25848.5264763777. The cubic root of 668146321 is about 874.2262857359.

The spelling of 668146321 in words is "six hundred sixty-eight million, one hundred forty-six thousand, three hundred twenty-one".