664744205 has 16 divisors (see below), whose sum is σ = 810149040. Its totient is φ = 523519488.

The previous prime is 664744187. The next prime is 664744207. The reversal of 664744205 is 502447466.

It can be written as a sum of positive squares in 8 ways, for example, as 8462281 + 656281924 = 2909^2 + 25618^2 .

It is a cyclic number.

It is not a de Polignac number, because 664744205 - 2⁶ = 664744141 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664744207) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 236951 + ... + 239739.

It is an arithmetic number, because the mean of its divisors is an integer number (50634315).

Almost surely, 2^664744205 is an apocalyptic number.

It is an amenable number.

664744205 is a deficient number, since it is larger than the sum of its proper divisors (145404835).

664744205 is a wasteful number, since it uses less digits than its factorization.

664744205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3520.

The product of its (nonzero) digits is 161280, while the sum is 38.

The square root of 664744205 is about 25782.6337871056. The cubic root of 664744205 is about 872.7399438051.

The spelling of 664744205 in words is "six hundred sixty-four million, seven hundred forty-four thousand, two hundred five".