243971109491 has 8 divisors (see below), whose sum is σ = 252398987280. Its totient is φ = 235544237152.

The previous prime is 243971109457. The next prime is 243971109497. The reversal of 243971109491 is 194901179342.

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-243971109491 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (243971109497) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 259976 + ... + 745338.

It is an arithmetic number, because the mean of its divisors is an integer number (31549873410).

Almost surely, 2^243971109491 is an apocalyptic number.

243971109491 is a deficient number, since it is larger than the sum of its proper divisors (8427877789).

243971109491 is a wasteful number, since it uses less digits than its factorization.

243971109491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 502725.

The product of its (nonzero) digits is 489888, while the sum is 50.

The spelling of 243971109491 in words is "two hundred forty-three billion, nine hundred seventy-one million, one hundred nine thousand, four hundred ninety-one".