648241309 has 2 divisors, whose sum is σ = 648241310. Its totient is φ = 648241308.

The previous prime is 648241291. The next prime is 648241313. The reversal of 648241309 is 903142846.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 391921209 + 256320100 = 19797^2 + 16010^2 .

It is a cyclic number.

It is not a de Polignac number, because 648241309 - 2⁹ = 648240797 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (648241409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 324120654 + 324120655.

It is an arithmetic number, because the mean of its divisors is an integer number (324120655).

Almost surely, 2^648241309 is an apocalyptic number.

It is an amenable number.

648241309 is a deficient number, since it is larger than the sum of its proper divisors (1).

648241309 is an equidigital number, since it uses as much as digits as its factorization.

648241309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 41472, while the sum is 37.

The square root of 648241309 is about 25460.5834379340. The cubic root of 648241309 is about 865.4571448418.

The spelling of 648241309 in words is "six hundred forty-eight million, two hundred forty-one thousand, three hundred nine".