648809 has 6 divisors (see below), whose sum is σ = 754794. Its totient is φ = 556080.

The previous prime is 648803. The next prime is 648841. The reversal of 648809 is 908846.

It can be written as a sum of positive squares in only one way, i.e., 648025 + 784 = 805^2 + 28^2 .

It is not a de Polignac number, because 648809 - 2¹⁶ = 583273 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 648809.

It is not an unprimeable number, because it can be changed into a prime (648803) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6572 + ... + 6669.

It is an arithmetic number, because the mean of its divisors is an integer number (125799).

2⁶⁴⁸⁸⁰⁹ is an apocalyptic number.

It is an amenable number.

648809 is a deficient number, since it is larger than the sum of its proper divisors (105985).

648809 is a wasteful number, since it uses less digits than its factorization.

648809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13255 (or 13248 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 35.

The square root of 648809 is about 805.4868093271. The cubic root of 648809 is about 86.5709709679.

The spelling of 648809 in words is "six hundred forty-eight thousand, eight hundred nine".