249661609 has 12 divisors (see below), whose sum is σ = 274365900. Its totient is φ = 226865408.

The previous prime is 249661591. The next prime is 249661613. The reversal of 249661609 is 906166942.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 21609 + 249640000 = 147^2 + 15800^2 .

It is not a de Polignac number, because 249661609 - 2¹⁹ = 249137321 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (249661649) 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 in 11 ways as a sum of consecutive naturals, for example, 6514 + ... + 23275.

It is an arithmetic number, because the mean of its divisors is an integer number (22863825).

Almost surely, 2^249661609 is an apocalyptic number.

249661609 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

249661609 is a deficient number, since it is larger than the sum of its proper divisors (24704291).

249661609 is a wasteful number, since it uses less digits than its factorization.

249661609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29852 (or 29835 counting only the distinct ones).

The product of its (nonzero) digits is 139968, while the sum is 43.

The square root of 249661609 is about 15800.6838143164. The cubic root of 249661609 is about 629.6761659801.

The spelling of 249661609 in words is "two hundred forty-nine million, six hundred sixty-one thousand, six hundred nine".