668477321 has 4 divisors (see below), whose sum is σ = 668861712. Its totient is φ = 668092932.

The previous prime is 668477317. The next prime is 668477353. The reversal of 668477321 is 123774866.

668477321 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 a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 123774866 = 2 ⋅61887433.

It is a cyclic number.

It is not a de Polignac number, because 668477321 - 2² = 668477317 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (668477311) 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, 189575 + ... + 193068.

It is an arithmetic number, because the mean of its divisors is an integer number (167215428).

Almost surely, 2^668477321 is an apocalyptic number.

It is an amenable number.

668477321 is a deficient number, since it is larger than the sum of its proper divisors (384391).

668477321 is a wasteful number, since it uses less digits than its factorization.

668477321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 384390.

The product of its digits is 338688, while the sum is 44.

The square root of 668477321 is about 25854.9283696552. The cubic root of 668477321 is about 874.3706259401.

The spelling of 668477321 in words is "six hundred sixty-eight million, four hundred seventy-seven thousand, three hundred twenty-one".