664206497 has 2 divisors, whose sum is σ = 664206498. Its totient is φ = 664206496.

The previous prime is 664206493. The next prime is 664206559. The reversal of 664206497 is 794602466.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 622203136 + 42003361 = 24944^2 + 6481^2 .

It is a cyclic number.

It is not a de Polignac number, because 664206497 - 2² = 664206493 is a prime.

It is a super-2 number, since 2×664206497² = 882340541314022018, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (664206493) 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, 332103248 + 332103249.

It is an arithmetic number, because the mean of its divisors is an integer number (332103249).

Almost surely, 2^664206497 is an apocalyptic number.

It is an amenable number.

664206497 is a deficient number, since it is larger than the sum of its proper divisors (1).

664206497 is an equidigital number, since it uses as much as digits as its factorization.

664206497 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 435456, while the sum is 44.

The square root of 664206497 is about 25772.2039608567. The cubic root of 664206497 is about 872.5045621171.

The spelling of 664206497 in words is "six hundred sixty-four million, two hundred six thousand, four hundred ninety-seven".