243984091 has 4 divisors (see below), whose sum is σ = 262752112. Its totient is φ = 225216072.

The previous prime is 243984067. The next prime is 243984101. The reversal of 243984091 is 190489342.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 243984091 - 2¹⁹ = 243459803 is a prime.

It is a super-2 number, since 2×243984091² = 119056473322192562, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (243984001) 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 3 ways as a sum of consecutive naturals, for example, 9383991 + ... + 9384016.

It is an arithmetic number, because the mean of its divisors is an integer number (65688028).

Almost surely, 2^243984091 is an apocalyptic number.

243984091 is a deficient number, since it is larger than the sum of its proper divisors (18768021).

243984091 is a wasteful number, since it uses less digits than its factorization.

243984091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18768020.

The product of its (nonzero) digits is 62208, while the sum is 40.

The square root of 243984091 is about 15619.9901088317. The cubic root of 243984091 is about 624.8663957619.

The spelling of 243984091 in words is "two hundred forty-three million, nine hundred eighty-four thousand, ninety-one".