243113551 has 4 divisors (see below), whose sum is σ = 243179152. Its totient is φ = 243047952.

The previous prime is 243113543. The next prime is 243113561. The reversal of 243113551 is 155311342.

It is a happy number.

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 243113551 - 2³ = 243113543 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 (243113561) 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, 26886 + ... + 34771.

It is an arithmetic number, because the mean of its divisors is an integer number (60794788).

Almost surely, 2^243113551 is an apocalyptic number.

243113551 is a deficient number, since it is larger than the sum of its proper divisors (65601).

243113551 is an equidigital number, since it uses as much as digits as its factorization.

243113551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65600.

The product of its digits is 1800, while the sum is 25.

The square root of 243113551 is about 15592.0989927591. The cubic root of 243113551 is about 624.1223316140.

Adding to 243113551 its reverse (155311342), we get a palindrome (398424893).

The spelling of 243113551 in words is "two hundred forty-three million, one hundred thirteen thousand, five hundred fifty-one".