243320231551 has 4 divisors (see below), whose sum is σ = 243629406712. Its totient is φ = 243011056392.

The previous prime is 243320231527. The next prime is 243320231579. The reversal of 243320231551 is 155132023342.

243320231551 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 243320231551 - 2¹³ = 243320223359 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (243320231251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 154586400 + ... + 154587973.

It is an arithmetic number, because the mean of its divisors is an integer number (60907351678).

Almost surely, 2^243320231551 is an apocalyptic number.

243320231551 is a deficient number, since it is larger than the sum of its proper divisors (309175161).

243320231551 is an equidigital number, since it uses as much as digits as its factorization.

243320231551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 309175160.

The product of its (nonzero) digits is 21600, while the sum is 31.

Adding to 243320231551 its reverse (155132023342), we get a palindrome (398452254893).

The spelling of 243320231551 in words is "two hundred forty-three billion, three hundred twenty million, two hundred thirty-one thousand, five hundred fifty-one".