18549943 has 2 divisors, whose sum is σ = 18549944. Its totient is φ = 18549942.

The previous prime is 18549931. The next prime is 18549959. The reversal of 18549943 is 34994581.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18549943 - 2²¹ = 16452791 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18549943.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18549143) 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, 9274971 + 9274972.

It is an arithmetic number, because the mean of its divisors is an integer number (9274972).

Almost surely, 2^18549943 is an apocalyptic number.

18549943 is a deficient number, since it is larger than the sum of its proper divisors (1).

18549943 is an equidigital number, since it uses as much as digits as its factorization.

18549943 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 155520, while the sum is 43.

The square root of 18549943 is about 4306.9644762872. The cubic root of 18549943 is about 264.7164071913.

The spelling of 18549943 in words is "eighteen million, five hundred forty-nine thousand, nine hundred forty-three".