249509609 has 2 divisors, whose sum is σ = 249509610. Its totient is φ = 249509608.

The previous prime is 249509597. The next prime is 249509627. The reversal of 249509609 is 906905942.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 217474009 + 32035600 = 14747^2 + 5660^2 .

It is a cyclic number.

It is not a de Polignac number, because 249509609 - 2⁴ = 249509593 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 249509609.

It is not a weakly prime, because it can be changed into another prime (249509009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 124754804 + 124754805.

It is an arithmetic number, because the mean of its divisors is an integer number (124754805).

Almost surely, 2^249509609 is an apocalyptic number.

It is an amenable number.

249509609 is a deficient number, since it is larger than the sum of its proper divisors (1).

249509609 is an equidigital number, since it uses as much as digits as its factorization.

249509609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 174960, while the sum is 44.

The square root of 249509609 is about 15795.8731635829. The cubic root of 249509609 is about 629.5483527000.

The spelling of 249509609 in words is "two hundred forty-nine million, five hundred nine thousand, six hundred nine".