18785149 has 2 divisors, whose sum is σ = 18785150. Its totient is φ = 18785148.

The previous prime is 18785147. The next prime is 18785171. The reversal of 18785149 is 94158781.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18705625 + 79524 = 4325^2 + 282^2 .

It is an emirp because it is prime and its reverse (94158781) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18785149 - 2¹ = 18785147 is a prime.

Together with 18785147, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18785147) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9392574 + 9392575.

It is an arithmetic number, because the mean of its divisors is an integer number (9392575).

Almost surely, 2^18785149 is an apocalyptic number.

It is an amenable number.

18785149 is a deficient number, since it is larger than the sum of its proper divisors (1).

18785149 is an equidigital number, since it uses as much as digits as its factorization.

18785149 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 80640, while the sum is 43.

The square root of 18785149 is about 4334.1837755222. The cubic root of 18785149 is about 265.8305448313.

The spelling of 18785149 in words is "eighteen million, seven hundred eighty-five thousand, one hundred forty-nine".