18809519 has 2 divisors, whose sum is σ = 18809520. Its totient is φ = 18809518.

The previous prime is 18809509. The next prime is 18809521. The reversal of 18809519 is 91590881.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18809519 is a prime.

It is a super-2 number, since 2×18809519² = 707596010022722, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 18809521, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18809509) 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, 9404759 + 9404760.

It is an arithmetic number, because the mean of its divisors is an integer number (9404760).

Almost surely, 2^18809519 is an apocalyptic number.

18809519 is a deficient number, since it is larger than the sum of its proper divisors (1).

18809519 is an equidigital number, since it uses as much as digits as its factorization.

18809519 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 25920, while the sum is 41.

The square root of 18809519 is about 4336.9942356429. The cubic root of 18809519 is about 265.9454492693.

The spelling of 18809519 in words is "eighteen million, eight hundred nine thousand, five hundred nineteen".