2566561687 has 2 divisors, whose sum is σ = 2566561688. Its totient is φ = 2566561686.

The previous prime is 2566561681. The next prime is 2566561783. The reversal of 2566561687 is 7861656652.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2566561687 - 2¹⁵ = 2566528919 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2566561681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1283280843 + 1283280844.

It is an arithmetic number, because the mean of its divisors is an integer number (1283280844).

Almost surely, 2^2566561687 is an apocalyptic number.

2566561687 is a deficient number, since it is larger than the sum of its proper divisors (1).

2566561687 is an equidigital number, since it uses as much as digits as its factorization.

2566561687 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3628800, while the sum is 52.

The square root of 2566561687 is about 50661.2444280635. The cubic root of 2566561687 is about 1369.1485442240.

The spelling of 2566561687 in words is "two billion, five hundred sixty-six million, five hundred sixty-one thousand, six hundred eighty-seven".