243643839 has 4 divisors (see below), whose sum is σ = 324858456. Its totient is φ = 162429224.

The previous prime is 243643823. The next prime is 243643879. The reversal of 243643839 is 938346342.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 243643839 - 2⁴ = 243643823 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 243643839.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (243643879) 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, 40607304 + ... + 40607309.

It is an arithmetic number, because the mean of its divisors is an integer number (81214614).

Almost surely, 2^243643839 is an apocalyptic number.

243643839 is a deficient number, since it is larger than the sum of its proper divisors (81214617).

243643839 is an equidigital number, since it uses as much as digits as its factorization.

243643839 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81214616.

The product of its digits is 373248, while the sum is 42.

The square root of 243643839 is about 15609.0947527395. The cubic root of 243643839 is about 624.5757880826.

It can be divided in two parts, 24364 and 3839, that added together give a triangular number (28203 = T₂₃₇).

The spelling of 243643839 in words is "two hundred forty-three million, six hundred forty-three thousand, eight hundred thirty-nine".