645016789 has 2 divisors, whose sum is σ = 645016790. Its totient is φ = 645016788.

The previous prime is 645016747. The next prime is 645016793. The reversal of 645016789 is 987610546.

645016789 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 439237764 + 205779025 = 20958^2 + 14345^2 .

It is a cyclic number.

It is not a de Polignac number, because 645016789 - 2¹⁹ = 644492501 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (645016189) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322508394 + 322508395.

It is an arithmetic number, because the mean of its divisors is an integer number (322508395).

Almost surely, 2^645016789 is an apocalyptic number.

It is an amenable number.

645016789 is a deficient number, since it is larger than the sum of its proper divisors (1).

645016789 is an equidigital number, since it uses as much as digits as its factorization.

645016789 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 362880, while the sum is 46.

The square root of 645016789 is about 25397.1807293644. The cubic root of 645016789 is about 864.0197562962.

The spelling of 645016789 in words is "six hundred forty-five million, sixteen thousand, seven hundred eighty-nine".