664561099 has 2 divisors, whose sum is σ = 664561100. Its totient is φ = 664561098.

The previous prime is 664561069. The next prime is 664561109. The reversal of 664561099 is 990165466.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 664561099 - 2⁵ = 664561067 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (664561069) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332280549 + 332280550.

It is an arithmetic number, because the mean of its divisors is an integer number (332280550).

Almost surely, 2^664561099 is an apocalyptic number.

664561099 is a deficient number, since it is larger than the sum of its proper divisors (1).

664561099 is an equidigital number, since it uses as much as digits as its factorization.

664561099 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 349920, while the sum is 46.

The square root of 664561099 is about 25779.0825864692. The cubic root of 664561099 is about 872.6598034072.

The spelling of 664561099 in words is "six hundred sixty-four million, five hundred sixty-one thousand, ninety-nine".