243889321 has 8 divisors (see below), whose sum is σ = 262942344. Its totient is φ = 224878080.

The previous prime is 243889291. The next prime is 243889337. The reversal of 243889321 is 123988342.

243889321 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 1651225 + 242238096 = 1285^2 + 15564^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 243889321 - 2⁹ = 243888809 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (243884321) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2265 + ... + 22201.

It is an arithmetic number, because the mean of its divisors is an integer number (32867793).

Almost surely, 2^243889321 is an apocalyptic number.

It is an amenable number.

243889321 is a deficient number, since it is larger than the sum of its proper divisors (19053023).

243889321 is a wasteful number, since it uses less digits than its factorization.

243889321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20891.

The product of its digits is 82944, while the sum is 40.

The square root of 243889321 is about 15616.9562015138. The cubic root of 243889321 is about 624.7854802985.

The spelling of 243889321 in words is "two hundred forty-three million, eight hundred eighty-nine thousand, three hundred twenty-one".