643215347 has 2 divisors, whose sum is σ = 643215348. Its totient is φ = 643215346.

The previous prime is 643215317. The next prime is 643215403. The reversal of 643215347 is 743512346.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 643215347 - 2⁶ = 643215283 is a prime.

It is equal to p_33459038 and since 643215347 and 33459038 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (643215317) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321607673 + 321607674.

It is an arithmetic number, because the mean of its divisors is an integer number (321607674).

Almost surely, 2^643215347 is an apocalyptic number.

643215347 is a deficient number, since it is larger than the sum of its proper divisors (1).

643215347 is an equidigital number, since it uses as much as digits as its factorization.

643215347 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 60480, while the sum is 35.

The square root of 643215347 is about 25361.6905390788. The cubic root of 643215347 is about 863.2146440527.

The spelling of 643215347 in words is "six hundred forty-three million, two hundred fifteen thousand, three hundred forty-seven".