646343924609 has 2 divisors, whose sum is σ = 646343924610. Its totient is φ = 646343924608.

The previous prime is 646343924599. The next prime is 646343924657. The reversal of 646343924609 is 906429343646.

646343924609 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 547718406400 + 98625518209 = 740080^2 + 314047^2 .

It is a cyclic number.

It is not a de Polignac number, because 646343924609 - 2⁴ = 646343924593 is a prime.

It is not a weakly prime, because it can be changed into another prime (646343924309) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323171962304 + 323171962305.

It is an arithmetic number, because the mean of its divisors is an integer number (323171962305).

Almost surely, 2^646343924609 is an apocalyptic number.

It is an amenable number.

646343924609 is a deficient number, since it is larger than the sum of its proper divisors (1).

646343924609 is an equidigital number, since it uses as much as digits as its factorization.

646343924609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 20155392, while the sum is 56.

The spelling of 646343924609 in words is "six hundred forty-six billion, three hundred forty-three million, nine hundred twenty-four thousand, six hundred nine".