648740565047909 has 2 divisors, whose sum is σ = 648740565047910. Its totient is φ = 648740565047908.

The previous prime is 648740565047803. The next prime is 648740565047933. The reversal of 648740565047909 is 909740565047846.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 624993900014884 + 23746665033025 = 24999878^2 + 4873055^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-648740565047909 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (648740565047989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 324370282523954 + 324370282523955.

It is an arithmetic number, because the mean of its divisors is an integer number (324370282523955).

Almost surely, 2^{648740565047909} is an apocalyptic number.

It is an amenable number.

648740565047909 is a deficient number, since it is larger than the sum of its proper divisors (1).

648740565047909 is an equidigital number, since it uses as much as digits as its factorization.

648740565047909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1828915200, while the sum is 74.

The spelling of 648740565047909 in words is "six hundred forty-eight trillion, seven hundred forty billion, five hundred sixty-five million, forty-seven thousand, nine hundred nine".