18938149 has 2 divisors, whose sum is σ = 18938150. Its totient is φ = 18938148.

The previous prime is 18938147. The next prime is 18938159. The reversal of 18938149 is 94183981.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18792225 + 145924 = 4335^2 + 382^2 .

It is a cyclic number.

It is not a de Polignac number, because 18938149 - 2¹ = 18938147 is a prime.

Together with 18938147, 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 (18938141) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9469074 + 9469075.

It is an arithmetic number, because the mean of its divisors is an integer number (9469075).

Almost surely, 2^18938149 is an apocalyptic number.

It is an amenable number.

18938149 is a deficient number, since it is larger than the sum of its proper divisors (1).

18938149 is an equidigital number, since it uses as much as digits as its factorization.

18938149 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 62208, while the sum is 43.

The square root of 18938149 is about 4351.7983638951. The cubic root of 18938149 is about 266.5503004435.

The spelling of 18938149 in words is "eighteen million, nine hundred thirty-eight thousand, one hundred forty-nine".