243555431 has 6 divisors (see below), whose sum is σ = 283319640. Its totient is φ = 208761756.

The previous prime is 243555421. The next prime is 243555439. The reversal of 243555431 is 134555342.

It is a happy number.

243555431 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a de Polignac number, because none of the positive numbers 2^k-243555431 is a prime.

It is a super-2 number, since 2×243555431² = 118638495939191522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (243555439) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2485211 + ... + 2485308.

It is an arithmetic number, because the mean of its divisors is an integer number (47219940).

Almost surely, 2^243555431 is an apocalyptic number.

243555431 is a deficient number, since it is larger than the sum of its proper divisors (39764209).

243555431 is an equidigital number, since it uses as much as digits as its factorization.

243555431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4970533 (or 4970526 counting only the distinct ones).

The product of its digits is 36000, while the sum is 32.

The square root of 243555431 is about 15606.2625570634. The cubic root of 243555431 is about 624.5002349357.

The spelling of 243555431 in words is "two hundred forty-three million, five hundred fifty-five thousand, four hundred thirty-one".