664767673 has 4 divisors (see below), whose sum is σ = 669002020. Its totient is φ = 660533328.

The previous prime is 664767661. The next prime is 664767709. The reversal of 664767673 is 376767466.

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 311628409 + 353139264 = 17653^2 + 18792^2 .

It is a cyclic number.

It is not a de Polignac number, because 664767673 - 2¹⁷ = 664636601 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 664767673.

It is not an unprimeable number, because it can be changed into a prime (664767373) 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, 2116938 + ... + 2117251.

It is an arithmetic number, because the mean of its divisors is an integer number (167250505).

Almost surely, 2^664767673 is an apocalyptic number.

It is an amenable number.

664767673 is a deficient number, since it is larger than the sum of its proper divisors (4234347).

664767673 is a wasteful number, since it uses less digits than its factorization.

664767673 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4234346.

The product of its digits is 5334336, while the sum is 52.

The square root of 664767673 is about 25783.0888956308. The cubic root of 664767673 is about 872.7502140312.

The spelling of 664767673 in words is "six hundred sixty-four million, seven hundred sixty-seven thousand, six hundred seventy-three".