243320401 has 4 divisors (see below), whose sum is σ = 244199092. Its totient is φ = 242441712.

The previous prime is 243320387. The next prime is 243320431. The reversal of 243320401 is 104023342.

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 90155025 + 153165376 = 9495^2 + 12376^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-243320401 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (243320431) 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 3 ways as a sum of consecutive naturals, for example, 438930 + ... + 439483.

It is an arithmetic number, because the mean of its divisors is an integer number (61049773).

Almost surely, 2^243320401 is an apocalyptic number.

It is an amenable number.

243320401 is a deficient number, since it is larger than the sum of its proper divisors (878691).

243320401 is an equidigital number, since it uses as much as digits as its factorization.

243320401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 878690.

The product of its (nonzero) digits is 576, while the sum is 19.

The square root of 243320401 is about 15598.7307496475. The cubic root of 243320401 is about 624.2992902229.

Adding to 243320401 its reverse (104023342), we get a palindrome (347343743).

The spelling of 243320401 in words is "two hundred forty-three million, three hundred twenty thousand, four hundred one".