18206689 has 2 divisors, whose sum is σ = 18206690. Its totient is φ = 18206688.

The previous prime is 18206687. The next prime is 18206707. The reversal of 18206689 is 98660281.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17139600 + 1067089 = 4140^2 + 1033^2 .

It is an emirp because it is prime and its reverse (98660281) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18206689 - 2¹ = 18206687 is a prime.

Together with 18206687, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18206687) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9103344 + 9103345.

It is an arithmetic number, because the mean of its divisors is an integer number (9103345).

Almost surely, 2^18206689 is an apocalyptic number.

It is an amenable number.

18206689 is a deficient number, since it is larger than the sum of its proper divisors (1).

18206689 is an equidigital number, since it uses as much as digits as its factorization.

18206689 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 41472, while the sum is 40.

The square root of 18206689 is about 4266.9296924135. The cubic root of 18206689 is about 263.0734324387.

The spelling of 18206689 in words is "eighteen million, two hundred six thousand, six hundred eighty-nine".