243320345551 has 4 divisors (see below), whose sum is σ = 257633307072. Its totient is φ = 229007384032.

The previous prime is 243320345539. The next prime is 243320345621. The reversal of 243320345551 is 155543023342.

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

It is a cyclic number.

It is not a de Polignac number, because 243320345551 - 2²¹ = 243318248399 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 243320345551.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (243320345531) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7156480735 + ... + 7156480768.

It is an arithmetic number, because the mean of its divisors is an integer number (64408326768).

Almost surely, 2^243320345551 is an apocalyptic number.

243320345551 is a deficient number, since it is larger than the sum of its proper divisors (14312961521).

243320345551 is a wasteful number, since it uses less digits than its factorization.

243320345551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14312961520.

The product of its (nonzero) digits is 216000, while the sum is 37.

Adding to 243320345551 its reverse (155543023342), we get a palindrome (398863368893).

The spelling of 243320345551 in words is "two hundred forty-three billion, three hundred twenty million, three hundred forty-five thousand, five hundred fifty-one".