18983021 has 2 divisors, whose sum is σ = 18983022. Its totient is φ = 18983020.

The previous prime is 18983011. The next prime is 18983039. The reversal of 18983021 is 12038981.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10048900 + 8934121 = 3170^2 + 2989^2 .

It is an emirp because it is prime and its reverse (12038981) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18983021 - 2¹⁰ = 18981997 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18983011) 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, 9491510 + 9491511.

It is an arithmetic number, because the mean of its divisors is an integer number (9491511).

Almost surely, 2^18983021 is an apocalyptic number.

It is an amenable number.

18983021 is a deficient number, since it is larger than the sum of its proper divisors (1).

18983021 is an equidigital number, since it uses as much as digits as its factorization.

18983021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3456, while the sum is 32.

The square root of 18983021 is about 4356.9508833587. The cubic root of 18983021 is about 266.7606555842.

The spelling of 18983021 in words is "eighteen million, nine hundred eighty-three thousand, twenty-one".