664620571 has 2 divisors, whose sum is σ = 664620572. Its totient is φ = 664620570.

The previous prime is 664620511. The next prime is 664620587. The reversal of 664620571 is 175026466.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 664620571 - 2²⁷ = 530402843 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 664620571.

It is not a weakly prime, because it can be changed into another prime (664620511) 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, 332310285 + 332310286.

It is an arithmetic number, because the mean of its divisors is an integer number (332310286).

Almost surely, 2^664620571 is an apocalyptic number.

664620571 is a deficient number, since it is larger than the sum of its proper divisors (1).

664620571 is an equidigital number, since it uses as much as digits as its factorization.

664620571 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 60480, while the sum is 37.

The square root of 664620571 is about 25780.2360540007. The cubic root of 664620571 is about 872.6858342596.

The spelling of 664620571 in words is "six hundred sixty-four million, six hundred twenty thousand, five hundred seventy-one".