18373321 has 2 divisors, whose sum is σ = 18373322. Its totient is φ = 18373320.

The previous prime is 18373319. The next prime is 18373331. The reversal of 18373321 is 12337381.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11799225 + 6574096 = 3435^2 + 2564^2 .

It is a cyclic number.

It is not a de Polignac number, because 18373321 - 2¹ = 18373319 is a prime.

Together with 18373319, it forms a pair of twin primes.

It is equal to p_1173628 and since 18373321 and 1173628 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18373321.

It is not a weakly prime, because it can be changed into another prime (18373301) 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, 9186660 + 9186661.

It is an arithmetic number, because the mean of its divisors is an integer number (9186661).

Almost surely, 2^18373321 is an apocalyptic number.

It is an amenable number.

18373321 is a deficient number, since it is larger than the sum of its proper divisors (1).

18373321 is an equidigital number, since it uses as much as digits as its factorization.

18373321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3024, while the sum is 28.

The square root of 18373321 is about 4286.4112028596. The cubic root of 18373321 is about 263.8735668313.

The spelling of 18373321 in words is "eighteen million, three hundred seventy-three thousand, three hundred twenty-one".