643287091 has 2 divisors, whose sum is σ = 643287092. Its totient is φ = 643287090.

The previous prime is 643287083. The next prime is 643287097. The reversal of 643287091 is 190782346.

643287091 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 is a cyclic number.

It is not a de Polignac number, because 643287091 - 2³ = 643287083 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (643287097) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321643545 + 321643546.

It is an arithmetic number, because the mean of its divisors is an integer number (321643546).

Almost surely, 2^643287091 is an apocalyptic number.

643287091 is a deficient number, since it is larger than the sum of its proper divisors (1).

643287091 is an equidigital number, since it uses as much as digits as its factorization.

643287091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72576, while the sum is 40.

The square root of 643287091 is about 25363.1049163938. The cubic root of 643287091 is about 863.2467370727.

The spelling of 643287091 in words is "six hundred forty-three million, two hundred eighty-seven thousand, ninety-one".