243431021 has 8 divisors (see below), whose sum is σ = 256428000. Its totient is φ = 230452560.

The previous prime is 243431009. The next prime is 243431051. The reversal of 243431021 is 120134342.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-243431021 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 243430984 and 243431002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (243431051) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28511 + ... + 36051.

It is an arithmetic number, because the mean of its divisors is an integer number (32053500).

Almost surely, 2^243431021 is an apocalyptic number.

It is an amenable number.

243431021 is a deficient number, since it is larger than the sum of its proper divisors (12996979).

243431021 is a wasteful number, since it uses less digits than its factorization.

243431021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9259.

The product of its (nonzero) digits is 576, while the sum is 20.

The square root of 243431021 is about 15602.2761480497. The cubic root of 243431021 is about 624.3938836401.

Adding to 243431021 its reverse (120134342), we get a palindrome (363565363).

The spelling of 243431021 in words is "two hundred forty-three million, four hundred thirty-one thousand, twenty-one".