243440421 has 16 divisors (see below), whose sum is σ = 371356800. Its totient is φ = 138958848.

The previous prime is 243440419. The next prime is 243440429. The reversal of 243440421 is 124044342.

It is a happy number.

It is not a de Polignac number, because 243440421 - 2¹ = 243440419 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 243440391 and 243440400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (243440429) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15445 + ... + 26933.

It is an arithmetic number, because the mean of its divisors is an integer number (23209800).

Almost surely, 2^243440421 is an apocalyptic number.

243440421 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

243440421 is a deficient number, since it is larger than the sum of its proper divisors (127916379).

243440421 is a wasteful number, since it uses less digits than its factorization.

243440421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12508.

The product of its (nonzero) digits is 3072, while the sum is 24.

The square root of 243440421 is about 15602.5773832402. The cubic root of 243440421 is about 624.4019204506.

Adding to 243440421 its reverse (124044342), we get a palindrome (367484763).

The spelling of 243440421 in words is "two hundred forty-three million, four hundred forty thousand, four hundred twenty-one".