2565649 has 2 divisors, whose sum is σ = 2565650. Its totient is φ = 2565648.

The previous prime is 2565643. The next prime is 2565671. The reversal of 2565649 is 9465652.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1500625 + 1065024 = 1225^2 + 1032^2 .

It is a cyclic number.

It is not a de Polignac number, because 2565649 - 2¹¹ = 2563601 is a prime.

2565649 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (2565643) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1282824 + 1282825.

It is an arithmetic number, because the mean of its divisors is an integer number (1282825).

2^2565649 is an apocalyptic number.

It is an amenable number.

2565649 is a deficient number, since it is larger than the sum of its proper divisors (1).

2565649 is an equidigital number, since it uses as much as digits as its factorization.

2565649 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 64800, while the sum is 37.

The square root of 2565649 is about 1601.7643397204. The cubic root of 2565649 is about 136.8986232101.

The spelling of 2565649 in words is "two million, five hundred sixty-five thousand, six hundred forty-nine".