243241430021 has 4 divisors (see below), whose sum is σ = 257549749452. Its totient is φ = 228933110592.

The previous prime is 243241430017. The next prime is 243241430041. The reversal of 243241430021 is 120034142342.

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 192993276100 + 50248153921 = 439310^2 + 224161^2 .

It is a cyclic number.

It is not a de Polignac number, because 243241430021 - 2² = 243241430017 is a prime.

It is a super-2 number, since 2×243241430021² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (243241430041) 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, 7154159690 + ... + 7154159723.

It is an arithmetic number, because the mean of its divisors is an integer number (64387437363).

Almost surely, 2^243241430021 is an apocalyptic number.

It is an amenable number.

243241430021 is a deficient number, since it is larger than the sum of its proper divisors (14308319431).

243241430021 is a wasteful number, since it uses less digits than its factorization.

243241430021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14308319430.

The product of its (nonzero) digits is 4608, while the sum is 26.

Adding to 243241430021 its reverse (120034142342), we get a palindrome (363275572363).

The spelling of 243241430021 in words is "two hundred forty-three billion, two hundred forty-one million, four hundred thirty thousand, twenty-one".