643553219 has 2 divisors, whose sum is σ = 643553220. Its totient is φ = 643553218.

The previous prime is 643553213. The next prime is 643553221. The reversal of 643553219 is 912355346.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 643553219 - 2⁴ = 643553203 is a prime.

It is a super-2 number, since 2×643553219² = 828321491370523922, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 643553221, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (643553213) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321776609 + 321776610.

It is an arithmetic number, because the mean of its divisors is an integer number (321776610).

Almost surely, 2^643553219 is an apocalyptic number.

643553219 is a deficient number, since it is larger than the sum of its proper divisors (1).

643553219 is an equidigital number, since it uses as much as digits as its factorization.

643553219 is an evil number, because the sum of its binary digits is even.

The product of its digits is 97200, while the sum is 38.

The square root of 643553219 is about 25368.3507347246. The cubic root of 643553219 is about 863.3657624440.

The spelling of 643553219 in words is "six hundred forty-three million, five hundred fifty-three thousand, two hundred nineteen".