18138049 has 2 divisors, whose sum is σ = 18138050. Its totient is φ = 18138048.

The previous prime is 18138041. The next prime is 18138061. The reversal of 18138049 is 94083181.

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., 14197824 + 3940225 = 3768^2 + 1985^2 .

It is an emirp because it is prime and its reverse (94083181) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18138049 - 2³ = 18138041 is a prime.

It is not a weakly prime, because it can be changed into another prime (18138041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9069024 + 9069025.

It is an arithmetic number, because the mean of its divisors is an integer number (9069025).

Almost surely, 2^18138049 is an apocalyptic number.

It is an amenable number.

18138049 is a deficient number, since it is larger than the sum of its proper divisors (1).

18138049 is an equidigital number, since it uses as much as digits as its factorization.

18138049 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6912, while the sum is 34.

The square root of 18138049 is about 4258.8788430760. The cubic root of 18138049 is about 262.7424167263.

The spelling of 18138049 in words is "eighteen million, one hundred thirty-eight thousand, forty-nine".