2555561 has 2 divisors, whose sum is σ = 2555562. Its totient is φ = 2555560.

The previous prime is 2555551. The next prime is 2555569. The reversal of 2555561 is 1655552.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2343961 + 211600 = 1531^2 + 460^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2555561 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 (2555569) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1277780 + 1277781.

It is an arithmetic number, because the mean of its divisors is an integer number (1277781).

2^2555561 is an apocalyptic number.

It is an amenable number.

2555561 is a deficient number, since it is larger than the sum of its proper divisors (1).

2555561 is an equidigital number, since it uses as much as digits as its factorization.

2555561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7500, while the sum is 29.

The square root of 2555561 is about 1598.6122106377. The cubic root of 2555561 is about 136.7189614136.

Subtracting from 2555561 its reverse (1655552), we obtain a palindrome (900009).

The spelling of 2555561 in words is "two million, five hundred fifty-five thousand, five hundred sixty-one".