19994321 has 2 divisors, whose sum is σ = 19994322. Its totient is φ = 19994320.

The previous prime is 19994309. The next prime is 19994323. The reversal of 19994321 is 12349991.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16516096 + 3478225 = 4064^2 + 1865^2 .

It is a cyclic number.

It is not a de Polignac number, because 19994321 - 2¹⁰ = 19993297 is a prime.

It is a Sophie Germain prime.

Together with 19994323, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (19994323) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9997160 + 9997161.

It is an arithmetic number, because the mean of its divisors is an integer number (9997161).

Almost surely, 2^19994321 is an apocalyptic number.

It is an amenable number.

19994321 is a deficient number, since it is larger than the sum of its proper divisors (1).

19994321 is an equidigital number, since it uses as much as digits as its factorization.

19994321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 17496, while the sum is 38.

The square root of 19994321 is about 4471.5009784188. The cubic root of 19994321 is about 271.4160672646.

The spelling of 19994321 in words is "nineteen million, nine hundred ninety-four thousand, three hundred twenty-one".