243225809 has 4 divisors (see below), whose sum is σ = 244569780. Its totient is φ = 241881840.

The previous prime is 243225793. The next prime is 243225841. The reversal of 243225809 is 908522342.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 70224400 + 173001409 = 8380^2 + 13153^2 .

It is a cyclic number.

It is not a de Polignac number, because 243225809 - 2⁴ = 243225793 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (243225509) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 671714 + ... + 672075.

It is an arithmetic number, because the mean of its divisors is an integer number (61142445).

Almost surely, 2^243225809 is an apocalyptic number.

It is an amenable number.

243225809 is a deficient number, since it is larger than the sum of its proper divisors (1343971).

243225809 is a wasteful number, since it uses less digits than its factorization.

243225809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1343970.

The product of its (nonzero) digits is 34560, while the sum is 35.

The square root of 243225809 is about 15595.6984133446. The cubic root of 243225809 is about 624.2183799329.

The spelling of 243225809 in words is "two hundred forty-three million, two hundred twenty-five thousand, eight hundred nine".