648309 has 4 divisors (see below), whose sum is σ = 864416. Its totient is φ = 432204.

The previous prime is 648293. The next prime is 648317. The reversal of 648309 is 903846.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 648309 - 2⁴ = 648293 is a prime.

It is a D-number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (648379) 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 3 ways as a sum of consecutive naturals, for example, 108049 + ... + 108054.

It is an arithmetic number, because the mean of its divisors is an integer number (216104).

2⁶⁴⁸³⁰⁹ is an apocalyptic number.

It is an amenable number.

648309 is a deficient number, since it is larger than the sum of its proper divisors (216107).

648309 is a wasteful number, since it uses less digits than its factorization.

648309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 216106.

The product of its (nonzero) digits is 5184, while the sum is 30.

The square root of 648309 is about 805.1763781930. The cubic root of 648309 is about 86.5487268203.

The spelling of 648309 in words is "six hundred forty-eight thousand, three hundred nine".