243851221 has 8 divisors (see below), whose sum is σ = 258626304. Its totient is φ = 229423920.

The previous prime is 243851219. The next prime is 243851243. The reversal of 243851221 is 122158342.

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

It is a cyclic number.

It is not a de Polignac number, because 243851221 - 2¹ = 243851219 is a prime.

It is a super-3 number, since 3×243851221³ (a number of 26 digits) contains 333 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 243851221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (243852221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 85501 + ... + 88306.

It is an arithmetic number, because the mean of its divisors is an integer number (32328288).

Almost surely, 2^243851221 is an apocalyptic number.

It is an amenable number.

243851221 is a deficient number, since it is larger than the sum of its proper divisors (14775083).

243851221 is a wasteful number, since it uses less digits than its factorization.

243851221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 173891.

The product of its digits is 3840, while the sum is 28.

The square root of 243851221 is about 15615.7363258989. The cubic root of 243851221 is about 624.7529442744.

The spelling of 243851221 in words is "two hundred forty-three million, eight hundred fifty-one thousand, two hundred twenty-one".