243865021 has 8 divisors (see below), whose sum is σ = 257690880. Its totient is φ = 230307792.

The previous prime is 243864989. The next prime is 243865043. The reversal of 243865021 is 120568342.

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 243865021 - 2⁵ = 243864989 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (243865421) 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, 65290 + ... + 68923.

It is an arithmetic number, because the mean of its divisors is an integer number (32211360).

Almost surely, 2^243865021 is an apocalyptic number.

It is an amenable number.

243865021 is a deficient number, since it is larger than the sum of its proper divisors (13825859).

243865021 is a wasteful number, since it uses less digits than its factorization.

243865021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 134315.

The product of its (nonzero) digits is 11520, while the sum is 31.

The square root of 243865021 is about 15616.1781816167. The cubic root of 243865021 is about 624.7647293675.

The spelling of 243865021 in words is "two hundred forty-three million, eight hundred sixty-five thousand, twenty-one".