243339905 has 8 divisors (see below), whose sum is σ = 292106472. Its totient is φ = 194606208.

The previous prime is 243339883. The next prime is 243339917. The reversal of 243339905 is 509933342.

It can be written as a sum of positive squares in 4 ways, for example, as 68492176 + 174847729 = 8276^2 + 13223^2 .

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 243339905 - 2¹² = 243335809 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13109 + ... + 25661.

It is an arithmetic number, because the mean of its divisors is an integer number (36513309).

Almost surely, 2^243339905 is an apocalyptic number.

It is an amenable number.

243339905 is a deficient number, since it is larger than the sum of its proper divisors (48766567).

243339905 is a wasteful number, since it uses less digits than its factorization.

243339905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16435.

The product of its (nonzero) digits is 87480, while the sum is 38.

The square root of 243339905 is about 15599.3559161909. The cubic root of 243339905 is about 624.3159705724.

The spelling of 243339905 in words is "two hundred forty-three million, three hundred thirty-nine thousand, nine hundred five".