18000643 has 2 divisors, whose sum is σ = 18000644. Its totient is φ = 18000642.

The previous prime is 18000629. The next prime is 18000649. The reversal of 18000643 is 34600081.

It is a strong prime.

It is an emirp because it is prime and its reverse (34600081) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18000643 - 2¹³ = 17992451 is a prime.

It is not a weakly prime, because it can be changed into another prime (18000649) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9000321 + 9000322.

It is an arithmetic number, because the mean of its divisors is an integer number (9000322).

Almost surely, 2^18000643 is an apocalyptic number.

18000643 is a deficient number, since it is larger than the sum of its proper divisors (1).

18000643 is an equidigital number, since it uses as much as digits as its factorization.

18000643 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 576, while the sum is 22.

The square root of 18000643 is about 4242.7164647193. The cubic root of 18000643 is about 262.0772600073.

The spelling of 18000643 in words is "eighteen million, six hundred forty-three", and thus it is an aban number.