243728191 has 8 divisors (see below), whose sum is σ = 281676960. Its totient is φ = 206562048.

The previous prime is 243728189. The next prime is 243728197. The reversal of 243728191 is 191827342.

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

It is not a de Polignac number, because 243728191 - 2¹ = 243728189 is a prime.

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 243728191.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (243728197) 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, 194986 + ... + 196231.

It is an arithmetic number, because the mean of its divisors is an integer number (35209620).

Almost surely, 2^243728191 is an apocalyptic number.

243728191 is a deficient number, since it is larger than the sum of its proper divisors (37948769).

243728191 is an equidigital number, since it uses as much as digits as its factorization.

243728191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 391313.

The product of its digits is 24192, while the sum is 37.

The square root of 243728191 is about 15611.7965333910. The cubic root of 243728191 is about 624.6478579508.

It can be divided in two parts, 2437 and 28191, that added together give a triangular number (30628 = T₂₄₇).

The spelling of 243728191 in words is "two hundred forty-three million, seven hundred twenty-eight thousand, one hundred ninety-one".