18954209 has 2 divisors, whose sum is σ = 18954210. Its totient is φ = 18954208.

The previous prime is 18954203. The next prime is 18954211. The reversal of 18954209 is 90245981.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18464209 + 490000 = 4297^2 + 700^2 .

It is a cyclic number.

It is not a de Polignac number, because 18954209 - 2⁴ = 18954193 is a prime.

Together with 18954211, 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 (18954203) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9477104 + 9477105.

It is an arithmetic number, because the mean of its divisors is an integer number (9477105).

Almost surely, 2^18954209 is an apocalyptic number.

It is an amenable number.

18954209 is a deficient number, since it is larger than the sum of its proper divisors (1).

18954209 is an equidigital number, since it uses as much as digits as its factorization.

18954209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 25920, while the sum is 38.

The square root of 18954209 is about 4353.6431870331. The cubic root of 18954209 is about 266.6256261494.

The spelling of 18954209 in words is "eighteen million, nine hundred fifty-four thousand, two hundred nine".