18982321 has 4 divisors (see below), whose sum is σ = 19340532. Its totient is φ = 18624112.

The previous prime is 18982297. The next prime is 18982331. The reversal of 18982321 is 12328981.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 15295921 + 3686400 = 3911^2 + 1920^2 .

It is a cyclic number.

It is not a de Polignac number, because 18982321 - 2¹³ = 18974129 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18982331) 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 in 3 ways as a sum of consecutive naturals, for example, 179026 + ... + 179131.

It is an arithmetic number, because the mean of its divisors is an integer number (4835133).

Almost surely, 2^18982321 is an apocalyptic number.

It is an amenable number.

18982321 is a deficient number, since it is larger than the sum of its proper divisors (358211).

18982321 is an equidigital number, since it uses as much as digits as its factorization.

18982321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 358210.

The product of its digits is 6912, while the sum is 34.

The square root of 18982321 is about 4356.8705512099. The cubic root of 18982321 is about 266.7573766057.

The spelling of 18982321 in words is "eighteen million, nine hundred eighty-two thousand, three hundred twenty-one".