643360309 has 2 divisors, whose sum is σ = 643360310. Its totient is φ = 643360308.

The previous prime is 643360303. The next prime is 643360321. The reversal of 643360309 is 903063346.

643360309 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., 548590084 + 94770225 = 23422^2 + 9735^2 .

It is a cyclic number.

It is not a de Polignac number, because 643360309 - 2¹⁵ = 643327541 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (643360303) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321680154 + 321680155.

It is an arithmetic number, because the mean of its divisors is an integer number (321680155).

Almost surely, 2^643360309 is an apocalyptic number.

It is an amenable number.

643360309 is a deficient number, since it is larger than the sum of its proper divisors (1).

643360309 is an equidigital number, since it uses as much as digits as its factorization.

643360309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 34992, while the sum is 34.

The square root of 643360309 is about 25364.5482711599. The cubic root of 643360309 is about 863.2794869925.

The spelling of 643360309 in words is "six hundred forty-three million, three hundred sixty thousand, three hundred nine".