664605005 has 4 divisors (see below), whose sum is σ = 797526012. Its totient is φ = 531684000.

The previous prime is 664604999. The next prime is 664605013. The reversal of 664605005 is 500506466.

664605005 = T₉₄₀₆ + T₉₄₀₇ + ... + T₉₄₂₀.

664605005 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: 500506466 = 2 ⋅250253233.

It can be written as a sum of positive squares in 2 ways, for example, as 464919844 + 199685161 = 21562^2 + 14131^2 .

It is not a de Polignac number, because 664605005 - 2¹⁰ = 664603981 is a prime.

It is a Duffinian number.

It is a Curzon number.

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, 66460496 + ... + 66460505.

It is an arithmetic number, because the mean of its divisors is an integer number (199381503).

Almost surely, 2^664605005 is an apocalyptic number.

It is an amenable number.

664605005 is a deficient number, since it is larger than the sum of its proper divisors (132921007).

664605005 is a wasteful number, since it uses less digits than its factorization.

664605005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 132921006.

The product of its (nonzero) digits is 21600, while the sum is 32.

The square root of 664605005 is about 25779.9341542992. The cubic root of 664605005 is about 872.6790211825.

The spelling of 664605005 in words is "six hundred sixty-four million, six hundred five thousand, five".