664413217 has 4 divisors (see below), whose sum is σ = 715521940. Its totient is φ = 613304496.

The previous prime is 664413209. The next prime is 664413221. The reversal of 664413217 is 712314466.

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 387656721 + 276756496 = 19689^2 + 16636^2 .

It is a cyclic number.

It is not a de Polignac number, because 664413217 - 2³ = 664413209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (664413017) 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, 25554342 + ... + 25554367.

It is an arithmetic number, because the mean of its divisors is an integer number (178880485).

Almost surely, 2^664413217 is an apocalyptic number.

It is an amenable number.

664413217 is a deficient number, since it is larger than the sum of its proper divisors (51108723).

664413217 is a wasteful number, since it uses less digits than its factorization.

664413217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51108722.

The product of its digits is 24192, while the sum is 34.

The square root of 664413217 is about 25776.2141712083. The cubic root of 664413217 is about 872.5950688273.

The spelling of 664413217 in words is "six hundred sixty-four million, four hundred thirteen thousand, two hundred seventeen".