20009443 has 2 divisors, whose sum is σ = 20009444. Its totient is φ = 20009442.

The previous prime is 20009441. The next prime is 20009447. The reversal of 20009443 is 34490002.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20009443 - 2¹ = 20009441 is a prime.

Together with 20009441, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (20009441) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10004721 + 10004722.

It is an arithmetic number, because the mean of its divisors is an integer number (10004722).

Almost surely, 2^20009443 is an apocalyptic number.

20009443 is a deficient number, since it is larger than the sum of its proper divisors (1).

20009443 is an equidigital number, since it uses as much as digits as its factorization.

20009443 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 864, while the sum is 22.

The square root of 20009443 is about 4473.1915899054. The cubic root of 20009443 is about 271.4844753470.

Adding to 20009443 its reverse (34490002), we get a palindrome (54499445).

The spelling of 20009443 in words is "twenty million, nine thousand, four hundred forty-three".