249055561 has 2 divisors, whose sum is σ = 249055562. Its totient is φ = 249055560.

The previous prime is 249055531. The next prime is 249055603. The reversal of 249055561 is 165550942.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 174768400 + 74287161 = 13220^2 + 8619^2 .

It is a cyclic number.

It is not a de Polignac number, because 249055561 - 2⁵ = 249055529 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 249055561.

It is not a weakly prime, because it can be changed into another prime (249055511) 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, 124527780 + 124527781.

It is an arithmetic number, because the mean of its divisors is an integer number (124527781).

Almost surely, 2^249055561 is an apocalyptic number.

It is an amenable number.

249055561 is a deficient number, since it is larger than the sum of its proper divisors (1).

249055561 is an equidigital number, since it uses as much as digits as its factorization.

249055561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 54000, while the sum is 37.

The square root of 249055561 is about 15781.4942575157. The cubic root of 249055561 is about 629.1662448564.

The spelling of 249055561 in words is "two hundred forty-nine million, fifty-five thousand, five hundred sixty-one".