18904819 has 2 divisors, whose sum is σ = 18904820. Its totient is φ = 18904818.

The previous prime is 18904807. The next prime is 18904849. The reversal of 18904819 is 91840981.

It is a weak prime.

It is an emirp because it is prime and its reverse (91840981) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18904819 - 2¹¹ = 18902771 is a prime.

It is a super-2 number, since 2×18904819² = 714784362845522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (18904849) 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, 9452409 + 9452410.

It is an arithmetic number, because the mean of its divisors is an integer number (9452410).

Almost surely, 2^18904819 is an apocalyptic number.

18904819 is a deficient number, since it is larger than the sum of its proper divisors (1).

18904819 is an equidigital number, since it uses as much as digits as its factorization.

18904819 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 20736, while the sum is 40.

The square root of 18904819 is about 4347.9672261874. The cubic root of 18904819 is about 266.3938378020.

The spelling of 18904819 in words is "eighteen million, nine hundred four thousand, eight hundred nineteen".