243978241 has 4 divisors (see below), whose sum is σ = 262745812. Its totient is φ = 225210672.

The previous prime is 243978233. The next prime is 243978283. The reversal of 243978241 is 142879342.

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

It can be written as a sum of positive squares in 2 ways, for example, as 75082225 + 168896016 = 8665^2 + 12996^2 .

It is a cyclic number.

It is not a de Polignac number, because 243978241 - 2³ = 243978233 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 243978194 and 243978203.

It is not an unprimeable number, because it can be changed into a prime (243978211) 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, 9383766 + ... + 9383791.

It is an arithmetic number, because the mean of its divisors is an integer number (65686453).

Almost surely, 2^243978241 is an apocalyptic number.

It is an amenable number.

243978241 is a deficient number, since it is larger than the sum of its proper divisors (18767571).

243978241 is a wasteful number, since it uses less digits than its factorization.

243978241 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18767570.

The product of its digits is 96768, while the sum is 40.

The square root of 243978241 is about 15619.8028476674. The cubic root of 243978241 is about 624.8614015870.

The spelling of 243978241 in words is "two hundred forty-three million, nine hundred seventy-eight thousand, two hundred forty-one".