243331405 has 4 divisors (see below), whose sum is σ = 291997692. Its totient is φ = 194665120.

The previous prime is 243331391. The next prime is 243331409. The reversal of 243331405 is 504133342.

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

It can be written as a sum of positive squares in 2 ways, for example, as 173475241 + 69856164 = 13171^2 + 8358^2 .

It is a de Polignac number, because none of the positive numbers 2^k-243331405 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 243331405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (243331409) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 24333136 + ... + 24333145.

It is an arithmetic number, because the mean of its divisors is an integer number (72999423).

Almost surely, 2^243331405 is an apocalyptic number.

It is an amenable number.

243331405 is a deficient number, since it is larger than the sum of its proper divisors (48666287).

243331405 is an equidigital number, since it uses as much as digits as its factorization.

243331405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48666286.

The product of its (nonzero) digits is 4320, while the sum is 25.

The square root of 243331405 is about 15599.0834666656. The cubic root of 243331405 is about 624.3087012516.

Adding to 243331405 its reverse (504133342), we get a palindrome (747464747).

The spelling of 243331405 in words is "two hundred forty-three million, three hundred thirty-one thousand, four hundred five".