643466189 has 2 divisors, whose sum is σ = 643466190. Its totient is φ = 643466188.

The previous prime is 643466137. The next prime is 643466209. The reversal of 643466189 is 981664346.

643466189 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., 630863689 + 12602500 = 25117^2 + 3550^2 .

It is a cyclic number.

It is not a de Polignac number, because 643466189 - 2¹² = 643462093 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (643466119) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321733094 + 321733095.

It is an arithmetic number, because the mean of its divisors is an integer number (321733095).

Almost surely, 2^643466189 is an apocalyptic number.

It is an amenable number.

643466189 is a deficient number, since it is larger than the sum of its proper divisors (1).

643466189 is an equidigital number, since it uses as much as digits as its factorization.

643466189 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 746496, while the sum is 47.

The square root of 643466189 is about 25366.6353503968. The cubic root of 643466189 is about 863.3268420111.

The spelling of 643466189 in words is "six hundred forty-three million, four hundred sixty-six thousand, one hundred eighty-nine".