243044020021 has 16 divisors (see below), whose sum is σ = 266652562176. Its totient is φ = 219688200000.

The previous prime is 243044019983. The next prime is 243044020039. The reversal of 243044020021 is 120020440342.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 243044020021 - 2⁷ = 243044019893 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 243044019974 and 243044020001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (243044020721) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19009651 + ... + 19022431.

It is an arithmetic number, because the mean of its divisors is an integer number (16665785136).

Almost surely, 2^243044020021 is an apocalyptic number.

It is an amenable number.

243044020021 is a deficient number, since it is larger than the sum of its proper divisors (23608542155).

243044020021 is a wasteful number, since it uses less digits than its factorization.

243044020021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22524.

The product of its (nonzero) digits is 1536, while the sum is 22.

Adding to 243044020021 its reverse (120020440342), we get a palindrome (363064460363).

The spelling of 243044020021 in words is "two hundred forty-three billion, forty-four million, twenty thousand, twenty-one".