18518503 has 2 divisors, whose sum is σ = 18518504. Its totient is φ = 18518502.

The previous prime is 18518477. The next prime is 18518531. The reversal of 18518503 is 30581581.

It is a weak prime.

It is an emirp because it is prime and its reverse (30581581) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18518503 - 2⁵ = 18518471 is a prime.

It is a super-2 number, since 2×18518503² = 685869906722018, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18518573) 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, 9259251 + 9259252.

It is an arithmetic number, because the mean of its divisors is an integer number (9259252).

Almost surely, 2^18518503 is an apocalyptic number.

18518503 is a deficient number, since it is larger than the sum of its proper divisors (1).

18518503 is an equidigital number, since it uses as much as digits as its factorization.

18518503 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4800, while the sum is 31.

The square root of 18518503 is about 4303.3130260301. The cubic root of 18518503 is about 264.5667680923.

The spelling of 18518503 in words is "eighteen million, five hundred eighteen thousand, five hundred three".