249875009 has 2 divisors, whose sum is σ = 249875010. Its totient is φ = 249875008.

The previous prime is 249874987. The next prime is 249875011. The reversal of 249875009 is 900578942.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 244234384 + 5640625 = 15628^2 + 2375^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-249875009 is a prime.

It is a Sophie Germain prime.

Together with 249875011, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (249875039) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 124937504 + 124937505.

It is an arithmetic number, because the mean of its divisors is an integer number (124937505).

Almost surely, 2^249875009 is an apocalyptic number.

It is an amenable number.

249875009 is a deficient number, since it is larger than the sum of its proper divisors (1).

249875009 is an equidigital number, since it uses as much as digits as its factorization.

249875009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 181440, while the sum is 44.

The square root of 249875009 is about 15807.4352442134. The cubic root of 249875009 is about 629.8555215849.

The spelling of 249875009 in words is "two hundred forty-nine million, eight hundred seventy-five thousand, nine".