243668149 has 2 divisors, whose sum is σ = 243668150. Its totient is φ = 243668148.

The previous prime is 243668147. The next prime is 243668177. The reversal of 243668149 is 941866342.

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., 196196049 + 47472100 = 14007^2 + 6890^2 .

It is a cyclic number.

It is not a de Polignac number, because 243668149 - 2¹ = 243668147 is a prime.

It is a super-3 number, since 3×243668149³ (a number of 26 digits) contains 333 as substring.

Together with 243668147, 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 (243668147) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121834074 + 121834075.

It is an arithmetic number, because the mean of its divisors is an integer number (121834075).

Almost surely, 2^243668149 is an apocalyptic number.

It is an amenable number.

243668149 is a deficient number, since it is larger than the sum of its proper divisors (1).

243668149 is an equidigital number, since it uses as much as digits as its factorization.

243668149 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 248832, while the sum is 43.

The square root of 243668149 is about 15609.8734459956. The cubic root of 243668149 is about 624.5965601140.

The spelling of 243668149 in words is "two hundred forty-three million, six hundred sixty-eight thousand, one hundred forty-nine".