2556641 has 2 divisors, whose sum is σ = 2556642. Its totient is φ = 2556640.

The previous prime is 2556607. The next prime is 2556661. The reversal of 2556641 is 1466552.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1392400 + 1164241 = 1180^2 + 1079^2 .

It is a cyclic number.

It is not a de Polignac number, because 2556641 - 2⁶ = 2556577 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (2556661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1278320 + 1278321.

It is an arithmetic number, because the mean of its divisors is an integer number (1278321).

2^2556641 is an apocalyptic number.

It is an amenable number.

2556641 is a deficient number, since it is larger than the sum of its proper divisors (1).

2556641 is an equidigital number, since it uses as much as digits as its factorization.

2556641 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7200, while the sum is 29.

The square root of 2556641 is about 1598.9499679477. The cubic root of 2556641 is about 136.7382182007.

The spelling of 2556641 in words is "two million, five hundred fifty-six thousand, six hundred forty-one".