220643999 has 2 divisors, whose sum is σ = 220644000. Its totient is φ = 220643998.

The previous prime is 220643993. The next prime is 220644023. The reversal of 220643999 is 999346022.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 220643999 - 2²⁰ = 219595423 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 (220643993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110321999 + 110322000.

It is an arithmetic number, because the mean of its divisors is an integer number (110322000).

Almost surely, 2^220643999 is an apocalyptic number.

220643999 is a deficient number, since it is larger than the sum of its proper divisors (1).

220643999 is an equidigital number, since it uses as much as digits as its factorization.

220643999 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 209952, while the sum is 44.

The square root of 220643999 is about 14854.0903120992. The cubic root of 220643999 is about 604.2695453143.

The spelling of 220643999 in words is "two hundred twenty million, six hundred forty-three thousand, nine hundred ninety-nine".