243138474739 has 4 divisors (see below), whose sum is σ = 248311633824. Its totient is φ = 237965315656.

The previous prime is 243138474727. The next prime is 243138474743. The reversal of 243138474739 is 937474831342.

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 243138474739 - 2³⁵ = 208778736371 is a prime.

It is a super-2 number, since 2×243138474739² (a number of 24 digits) contains 22 as substring.

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 243138474739.

It is not an unprimeable number, because it can be changed into a prime (243138474749) 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, 2586579472 + ... + 2586579565.

It is an arithmetic number, because the mean of its divisors is an integer number (62077908456).

Almost surely, 2^243138474739 is an apocalyptic number.

243138474739 is a deficient number, since it is larger than the sum of its proper divisors (5173159085).

243138474739 is an equidigital number, since it uses as much as digits as its factorization.

243138474739 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5173159084.

The product of its digits is 12192768, while the sum is 55.

The spelling of 243138474739 in words is "two hundred forty-three billion, one hundred thirty-eight million, four hundred seventy-four thousand, seven hundred thirty-nine".