18236549 has 2 divisors, whose sum is σ = 18236550. Its totient is φ = 18236548.

The previous prime is 18236527. The next prime is 18236551. The reversal of 18236549 is 94563281.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17222500 + 1014049 = 4150^2 + 1007^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18236549 is a prime.

Together with 18236551, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18236509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9118274 + 9118275.

It is an arithmetic number, because the mean of its divisors is an integer number (9118275).

Almost surely, 2^18236549 is an apocalyptic number.

It is an amenable number.

18236549 is a deficient number, since it is larger than the sum of its proper divisors (1).

18236549 is an equidigital number, since it uses as much as digits as its factorization.

18236549 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 51840, while the sum is 38.

The square root of 18236549 is about 4270.4272619962. The cubic root of 18236549 is about 263.2171723243.

The spelling of 18236549 in words is "eighteen million, two hundred thirty-six thousand, five hundred forty-nine".