649680569 has 2 divisors, whose sum is σ = 649680570. Its totient is φ = 649680568.

The previous prime is 649680541. The next prime is 649680571. The reversal of 649680569 is 965086946.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 575376169 + 74304400 = 23987^2 + 8620^2 .

It is a cyclic number.

It is not a de Polignac number, because 649680569 - 2²⁸ = 381245113 is a prime.

It is a super-2 number, since 2×649680569² = 844169683472327522, which contains 22 as substring.

Together with 649680571, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 649680569.

It is not a weakly prime, because it can be changed into another prime (649680539) 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, 324840284 + 324840285.

It is an arithmetic number, because the mean of its divisors is an integer number (324840285).

Almost surely, 2^649680569 is an apocalyptic number.

It is an amenable number.

649680569 is a deficient number, since it is larger than the sum of its proper divisors (1).

649680569 is an equidigital number, since it uses as much as digits as its factorization.

649680569 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2799360, while the sum is 53.

The square root of 649680569 is about 25488.8322408070. The cubic root of 649680569 is about 866.0971827957.

The spelling of 649680569 in words is "six hundred forty-nine million, six hundred eighty thousand, five hundred sixty-nine".