2557861 has 2 divisors, whose sum is σ = 2557862. Its totient is φ = 2557860.

The previous prime is 2557843. The next prime is 2557879. The reversal of 2557861 is 1687552.

2557861 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a balanced prime because it is at equal distance from previous prime (2557843) and next prime (2557879).

It can be written as a sum of positive squares in only one way, i.e., 2461761 + 96100 = 1569^2 + 310^2 .

It is a cyclic number.

It is not a de Polignac number, because 2557861 - 2¹³ = 2549669 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2557561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1278930 + 1278931.

It is an arithmetic number, because the mean of its divisors is an integer number (1278931).

2^2557861 is an apocalyptic number.

It is an amenable number.

2557861 is a deficient number, since it is larger than the sum of its proper divisors (1).

2557861 is an equidigital number, since it uses as much as digits as its factorization.

2557861 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 16800, while the sum is 34.

The square root of 2557861 is about 1599.3314228139. The cubic root of 2557861 is about 136.7599647161.

The spelling of 2557861 in words is "two million, five hundred fifty-seven thousand, eight hundred sixty-one".