249920609 has 2 divisors, whose sum is σ = 249920610. Its totient is φ = 249920608.

The previous prime is 249920591. The next prime is 249920651. The reversal of 249920609 is 906029942.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 245392225 + 4528384 = 15665^2 + 2128^2 .

It is a cyclic number.

It is not a de Polignac number, because 249920609 - 2⁸ = 249920353 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (249920659) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 124960304 + 124960305.

It is an arithmetic number, because the mean of its divisors is an integer number (124960305).

Almost surely, 2^249920609 is an apocalyptic number.

It is an amenable number.

249920609 is a deficient number, since it is larger than the sum of its proper divisors (1).

249920609 is an equidigital number, since it uses as much as digits as its factorization.

249920609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 69984, while the sum is 41.

The square root of 249920609 is about 15808.8775376369. The cubic root of 249920609 is about 629.8938336260.

The spelling of 249920609 in words is "two hundred forty-nine million, nine hundred twenty thousand, six hundred nine".