243290391 has 8 divisors (see below), whose sum is σ = 324568944. Its totient is φ = 162102720.

The previous prime is 243290381. The next prime is 243290401. The reversal of 243290391 is 193092342.

It is an interprime number because it is at equal distance from previous prime (243290381) and next prime (243290401).

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

It is not a de Polignac number, because 243290391 - 2¹⁴ = 243274007 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (243290371) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16206 + ... + 27371.

It is an arithmetic number, because the mean of its divisors is an integer number (40571118).

Almost surely, 2^243290391 is an apocalyptic number.

243290391 is a deficient number, since it is larger than the sum of its proper divisors (81278553).

243290391 is a wasteful number, since it uses less digits than its factorization.

243290391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45441.

The product of its (nonzero) digits is 11664, while the sum is 33.

The square root of 243290391 is about 15597.7687827458. The cubic root of 243290391 is about 624.2736231163.

The spelling of 243290391 in words is "two hundred forty-three million, two hundred ninety thousand, three hundred ninety-one".