18793321 has 2 divisors, whose sum is σ = 18793322. Its totient is φ = 18793320.

The previous prime is 18793319. The next prime is 18793331. The reversal of 18793321 is 12339781.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15713296 + 3080025 = 3964^2 + 1755^2 .

It is a cyclic number.

It is not a de Polignac number, because 18793321 - 2¹ = 18793319 is a prime.

Together with 18793319, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (18793331) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9396660 + 9396661.

It is an arithmetic number, because the mean of its divisors is an integer number (9396661).

Almost surely, 2^18793321 is an apocalyptic number.

It is an amenable number.

18793321 is a deficient number, since it is larger than the sum of its proper divisors (1).

18793321 is an equidigital number, since it uses as much as digits as its factorization.

18793321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9072, while the sum is 34.

The square root of 18793321 is about 4335.1264110750. The cubic root of 18793321 is about 265.8690868427.

The spelling of 18793321 in words is "eighteen million, seven hundred ninety-three thousand, three hundred twenty-one".