243989143 has 4 divisors (see below), whose sum is σ = 247630840. Its totient is φ = 240347448.

The previous prime is 243989111. The next prime is 243989149. The reversal of 243989143 is 341989342.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 341989342 = 2 ⋅170994671.

It is a cyclic number.

It is not a de Polignac number, because 243989143 - 2⁵ = 243989111 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 243989143.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (243989149) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1820748 + ... + 1820881.

It is an arithmetic number, because the mean of its divisors is an integer number (61907710).

Almost surely, 2^243989143 is an apocalyptic number.

243989143 is a deficient number, since it is larger than the sum of its proper divisors (3641697).

243989143 is an equidigital number, since it uses as much as digits as its factorization.

243989143 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3641696.

The product of its digits is 186624, while the sum is 43.

The square root of 243989143 is about 15620.1518238460. The cubic root of 243989143 is about 624.8707086158.

The spelling of 243989143 in words is "two hundred forty-three million, nine hundred eighty-nine thousand, one hundred forty-three".