243309331 has 4 divisors (see below), whose sum is σ = 243365472. Its totient is φ = 243253192.

The previous prime is 243309281. The next prime is 243309343. The reversal of 243309331 is 133903342.

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 243309331 - 2²³ = 234920723 is a prime.

It is a super-2 number, since 2×243309331² = 118398861103335122, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 243309331.

It is not an unprimeable number, because it can be changed into a prime (243319331) 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, 20971 + ... + 30436.

It is an arithmetic number, because the mean of its divisors is an integer number (60841368).

Almost surely, 2^243309331 is an apocalyptic number.

243309331 is a deficient number, since it is larger than the sum of its proper divisors (56141).

243309331 is an equidigital number, since it uses as much as digits as its factorization.

243309331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56140.

The product of its (nonzero) digits is 5832, while the sum is 28.

The square root of 243309331 is about 15598.3759090490. The cubic root of 243309331 is about 624.2898224622.

The spelling of 243309331 in words is "two hundred forty-three million, three hundred nine thousand, three hundred thirty-one".