243951221 has 8 divisors (see below), whose sum is σ = 249242304. Its totient is φ = 238708800.

The previous prime is 243951163. The next prime is 243951223. The reversal of 243951221 is 122159342.

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 243951221 - 2¹⁸ = 243689077 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (243951223) 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, 1940 + ... + 22173.

It is an arithmetic number, because the mean of its divisors is an integer number (31155288).

Almost surely, 2^243951221 is an apocalyptic number.

It is an amenable number.

243951221 is a deficient number, since it is larger than the sum of its proper divisors (5291083).

243951221 is a wasteful number, since it uses less digits than its factorization.

243951221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24331.

The product of its digits is 4320, while the sum is 29.

The square root of 243951221 is about 15618.9378960287. The cubic root of 243951221 is about 624.8383334392.

The spelling of 243951221 in words is "two hundred forty-three million, nine hundred fifty-one thousand, two hundred twenty-one".