2568209561 has 2 divisors, whose sum is σ = 2568209562. Its totient is φ = 2568209560.

The previous prime is 2568209557. The next prime is 2568209603. The reversal of 2568209561 is 1659028652.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1630625161 + 937584400 = 40381^2 + 30620^2 .

It is a cyclic number.

It is not a de Polignac number, because 2568209561 - 2² = 2568209557 is a prime.

It is not a weakly prime, because it can be changed into another prime (2568239561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1284104780 + 1284104781.

It is an arithmetic number, because the mean of its divisors is an integer number (1284104781).

Almost surely, 2^2568209561 is an apocalyptic number.

It is an amenable number.

2568209561 is a deficient number, since it is larger than the sum of its proper divisors (1).

2568209561 is an equidigital number, since it uses as much as digits as its factorization.

2568209561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 259200, while the sum is 44.

The square root of 2568209561 is about 50677.5054733360. The cubic root of 2568209561 is about 1369.4415044656.

The spelling of 2568209561 in words is "two billion, five hundred sixty-eight million, two hundred nine thousand, five hundred sixty-one".