648605509 has 2 divisors, whose sum is σ = 648605510. Its totient is φ = 648605508.

The previous prime is 648605501. The next prime is 648605533. The reversal of 648605509 is 905506846.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 483560100 + 165045409 = 21990^2 + 12847^2 .

It is a cyclic number.

It is not a de Polignac number, because 648605509 - 2³ = 648605501 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (648605501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 324302754 + 324302755.

It is an arithmetic number, because the mean of its divisors is an integer number (324302755).

Almost surely, 2^648605509 is an apocalyptic number.

It is an amenable number.

648605509 is a deficient number, since it is larger than the sum of its proper divisors (1).

648605509 is an equidigital number, since it uses as much as digits as its factorization.

648605509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 259200, while the sum is 43.

The square root of 648605509 is about 25467.7346656510. The cubic root of 648605509 is about 865.6191937974.

The spelling of 648605509 in words is "six hundred forty-eight million, six hundred five thousand, five hundred nine".