2556761 has 2 divisors, whose sum is σ = 2556762. Its totient is φ = 2556760.

The previous prime is 2556739. The next prime is 2556791. The reversal of 2556761 is 1676552.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1690000 + 866761 = 1300^2 + 931^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2556761 is a prime.

It is a super-2 number, since 2×2556761² = 13074053622242, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (2556791) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1278380 + 1278381.

It is an arithmetic number, because the mean of its divisors is an integer number (1278381).

2^2556761 is an apocalyptic number.

It is an amenable number.

2556761 is a deficient number, since it is larger than the sum of its proper divisors (1).

2556761 is an equidigital number, since it uses as much as digits as its factorization.

2556761 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12600, while the sum is 32.

The square root of 2556761 is about 1598.9874921337. The cubic root of 2556761 is about 136.7403575090.

The spelling of 2556761 in words is "two million, five hundred fifty-six thousand, seven hundred sixty-one".