664645567 has 2 divisors, whose sum is σ = 664645568. Its totient is φ = 664645566.

The previous prime is 664645543. The next prime is 664645571. The reversal of 664645567 is 765546466.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 664645567 - 2²⁷ = 530427839 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 664645567.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (664645537) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332322783 + 332322784.

It is an arithmetic number, because the mean of its divisors is an integer number (332322784).

Almost surely, 2^664645567 is an apocalyptic number.

664645567 is a deficient number, since it is larger than the sum of its proper divisors (1).

664645567 is an equidigital number, since it uses as much as digits as its factorization.

664645567 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3628800, while the sum is 49.

The square root of 664645567 is about 25780.7208394180. The cubic root of 664645567 is about 872.6967745277.

The spelling of 664645567 in words is "six hundred sixty-four million, six hundred forty-five thousand, five hundred sixty-seven".