18206939 has 2 divisors, whose sum is σ = 18206940. Its totient is φ = 18206938.

The previous prime is 18206917. The next prime is 18206953. The reversal of 18206939 is 93960281.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 18206939 - 2²⁰ = 17158363 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18206999) 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, 9103469 + 9103470.

It is an arithmetic number, because the mean of its divisors is an integer number (9103470).

Almost surely, 2^18206939 is an apocalyptic number.

18206939 is a deficient number, since it is larger than the sum of its proper divisors (1).

18206939 is an equidigital number, since it uses as much as digits as its factorization.

18206939 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 23328, while the sum is 38.

The square root of 18206939 is about 4266.9589873820. The cubic root of 18206939 is about 263.0746365393.

The spelling of 18206939 in words is "eighteen million, two hundred six thousand, nine hundred thirty-nine".