648775309 has 32 divisors (see below), whose sum is σ = 816865280. Its totient is φ = 501645312.

The previous prime is 648775291. The next prime is 648775313. The reversal of 648775309 is 903577846.

It is a happy number.

648775309 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 648775309 - 2¹⁵ = 648742541 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (648775399) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 843277 + ... + 844045.

It is an arithmetic number, because the mean of its divisors is an integer number (25527040).

Almost surely, 2^648775309 is an apocalyptic number.

It is an amenable number.

648775309 is a deficient number, since it is larger than the sum of its proper divisors (168089971).

648775309 is a wasteful number, since it uses less digits than its factorization.

648775309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 989.

The product of its (nonzero) digits is 1270080, while the sum is 49.

The square root of 648775309 is about 25471.0680773304. The cubic root of 648775309 is about 865.6947247185.

It can be divided in two parts, 6487 and 75309, that added together give a square (81796 = 286²).

The spelling of 648775309 in words is "six hundred forty-eight million, seven hundred seventy-five thousand, three hundred nine".