2566635649 has 2 divisors, whose sum is σ = 2566635650. Its totient is φ = 2566635648.

The previous prime is 2566635623. The next prime is 2566635719. The reversal of 2566635649 is 9465366652.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1844101249 + 722534400 = 42943^2 + 26880^2 .

It is a cyclic number.

It is not a de Polignac number, because 2566635649 - 2²¹ = 2564538497 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2566635596 and 2566635605.

It is not a weakly prime, because it can be changed into another prime (2566636649) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1283317824 + 1283317825.

It is an arithmetic number, because the mean of its divisors is an integer number (1283317825).

Almost surely, 2^2566635649 is an apocalyptic number.

It is an amenable number.

2566635649 is a deficient number, since it is larger than the sum of its proper divisors (1).

2566635649 is an equidigital number, since it uses as much as digits as its factorization.

2566635649 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6998400, while the sum is 52.

The square root of 2566635649 is about 50661.9743890820. The cubic root of 2566635649 is about 1369.1616959297.

The spelling of 2566635649 in words is "two billion, five hundred sixty-six million, six hundred thirty-five thousand, six hundred forty-nine".