245513561 has 2 divisors, whose sum is σ = 245513562. Its totient is φ = 245513560.

The previous prime is 245513557. The next prime is 245513579. The reversal of 245513561 is 165315542.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 245110336 + 403225 = 15656^2 + 635^2 .

It is a cyclic number.

It is not a de Polignac number, because 245513561 - 2² = 245513557 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 (245513551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 122756780 + 122756781.

It is an arithmetic number, because the mean of its divisors is an integer number (122756781).

Almost surely, 2^245513561 is an apocalyptic number.

It is an amenable number.

245513561 is a deficient number, since it is larger than the sum of its proper divisors (1).

245513561 is an equidigital number, since it uses as much as digits as its factorization.

245513561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 18000, while the sum is 32.

The square root of 245513561 is about 15668.8723589159. The cubic root of 245513561 is about 626.1693827591.

The spelling of 245513561 in words is "two hundred forty-five million, five hundred thirteen thousand, five hundred sixty-one".