664109 has 2 divisors, whose sum is σ = 664110. Its totient is φ = 664108.

The previous prime is 664099. The next prime is 664117. The reversal of 664109 is 901466.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 635209 + 28900 = 797^2 + 170^2 .

It is a cyclic number.

It is not a de Polignac number, because 664109 - 2⁸ = 663853 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (664199) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332054 + 332055.

It is an arithmetic number, because the mean of its divisors is an integer number (332055).

2⁶⁶⁴¹⁰⁹ is an apocalyptic number.

It is an amenable number.

664109 is a deficient number, since it is larger than the sum of its proper divisors (1).

664109 is an equidigital number, since it uses as much as digits as its factorization.

664109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1296, while the sum is 26.

The square root of 664109 is about 814.9288312485. The cubic root of 664109 is about 87.2461869199.

The spelling of 664109 in words is "six hundred sixty-four thousand, one hundred nine".