243991044563 has 4 divisors (see below), whose sum is σ = 278846908080. Its totient is φ = 209135181048.

The previous prime is 243991044559. The next prime is 243991044593. The reversal of 243991044563 is 365440199342.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 365440199342 = 2 ⋅182720099671.

It is a cyclic number.

It is not a de Polignac number, because 243991044563 - 2² = 243991044559 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (243991044523) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17427931748 + ... + 17427931761.

It is an arithmetic number, because the mean of its divisors is an integer number (69711727020).

Almost surely, 2^243991044563 is an apocalyptic number.

243991044563 is a deficient number, since it is larger than the sum of its proper divisors (34855863517).

243991044563 is an equidigital number, since it uses as much as digits as its factorization.

243991044563 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34855863516.

The product of its (nonzero) digits is 2799360, while the sum is 50.

The spelling of 243991044563 in words is "two hundred forty-three billion, nine hundred ninety-one million, forty-four thousand, five hundred sixty-three".