243904989 has 4 divisors (see below), whose sum is σ = 325206656. Its totient is φ = 162603324.

The previous prime is 243904943. The next prime is 243905009. The reversal of 243904989 is 989409342.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 243904989 - 2¹³ = 243896797 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 (243904189) 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, 40650829 + ... + 40650834.

It is an arithmetic number, because the mean of its divisors is an integer number (81301664).

Almost surely, 2^243904989 is an apocalyptic number.

It is an amenable number.

243904989 is a deficient number, since it is larger than the sum of its proper divisors (81301667).

243904989 is an equidigital number, since it uses as much as digits as its factorization.

243904989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81301666.

The product of its (nonzero) digits is 559872, while the sum is 48.

The square root of 243904989 is about 15617.4578277004. The cubic root of 243904989 is about 624.7988592214.

The spelling of 243904989 in words is "two hundred forty-three million, nine hundred four thousand, nine hundred eighty-nine".