18541559 has 2 divisors, whose sum is σ = 18541560. Its totient is φ = 18541558.

The previous prime is 18541541. The next prime is 18541561. The reversal of 18541559 is 95514581.

It is a strong prime.

It is an emirp because it is prime and its reverse (95514581) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18541559 - 2¹⁶ = 18476023 is a prime.

It is a Sophie Germain prime.

Together with 18541561, 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 (18541529) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9270779 + 9270780.

It is an arithmetic number, because the mean of its divisors is an integer number (9270780).

Almost surely, 2^18541559 is an apocalyptic number.

18541559 is a deficient number, since it is larger than the sum of its proper divisors (1).

18541559 is an equidigital number, since it uses as much as digits as its factorization.

18541559 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 36000, while the sum is 38.

The square root of 18541559 is about 4305.9910589782. The cubic root of 18541559 is about 264.6765199743.

The spelling of 18541559 in words is "eighteen million, five hundred forty-one thousand, five hundred fifty-nine".