18813643 has 2 divisors, whose sum is σ = 18813644. Its totient is φ = 18813642.

The previous prime is 18813617. The next prime is 18813673. The reversal of 18813643 is 34631881.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18813643 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 18813599 and 18813608.

It is not a weakly prime, because it can be changed into another prime (18813673) 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, 9406821 + 9406822.

It is an arithmetic number, because the mean of its divisors is an integer number (9406822).

Almost surely, 2^18813643 is an apocalyptic number.

18813643 is a deficient number, since it is larger than the sum of its proper divisors (1).

18813643 is an equidigital number, since it uses as much as digits as its factorization.

18813643 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13824, while the sum is 34.

The square root of 18813643 is about 4337.4696540725. The cubic root of 18813643 is about 265.9648840900.

It can be divided in two parts, 188 and 13643, that added together give a palindrome (13831).

The spelling of 18813643 in words is "eighteen million, eight hundred thirteen thousand, six hundred forty-three".