243866857 has 8 divisors (see below), whose sum is σ = 262966536. Its totient is φ = 224815872.

The previous prime is 243866839. The next prime is 243866869. The reversal of 243866857 is 758668342.

243866857 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 2499561 + 241367296 = 1581^2 + 15536^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-243866857 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 243866857.

It is not an unprimeable number, because it can be changed into a prime (243866897) 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, 1408 + ... + 22129.

It is an arithmetic number, because the mean of its divisors is an integer number (32870817).

Almost surely, 2^243866857 is an apocalyptic number.

It is an amenable number.

243866857 is a deficient number, since it is larger than the sum of its proper divisors (19099679).

243866857 is a wasteful number, since it uses less digits than its factorization.

243866857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24347.

The product of its digits is 1935360, while the sum is 49.

The square root of 243866857 is about 15616.2369666959. The cubic root of 243866857 is about 624.7662972637.

The spelling of 243866857 in words is "two hundred forty-three million, eight hundred sixty-six thousand, eight hundred fifty-seven".