648509 has 2 divisors, whose sum is σ = 648510. Its totient is φ = 648508.

The previous prime is 648481. The next prime is 648563. The reversal of 648509 is 905846.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 648025 + 484 = 805^2 + 22^2 .

It is a cyclic number.

It is not a de Polignac number, because 648509 - 2¹⁶ = 582973 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 648509.

It is not a weakly prime, because it can be changed into another prime (648709) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 324254 + 324255.

It is an arithmetic number, because the mean of its divisors is an integer number (324255).

2⁶⁴⁸⁵⁰⁹ is an apocalyptic number.

It is an amenable number.

648509 is a deficient number, since it is larger than the sum of its proper divisors (1).

648509 is an equidigital number, since it uses as much as digits as its factorization.

648509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 648509 is about 805.3005650066. The cubic root of 648509 is about 86.5576258513.

The spelling of 648509 in words is "six hundred forty-eight thousand, five hundred nine".