2557806443561 has 4 divisors (see below), whose sum is σ = 2669015419392. Its totient is φ = 2446597467732.

The previous prime is 2557806443551. The next prime is 2557806443581. The reversal of 2557806443561 is 1653446087552.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2557806443561 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2557806443497 and 2557806443506.

It is not an unprimeable number, because it can be changed into a prime (2557806443551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 55604487881 + ... + 55604487926.

It is an arithmetic number, because the mean of its divisors is an integer number (667253854848).

Almost surely, 2^{2557806443561} is an apocalyptic number.

It is an amenable number.

2557806443561 is a deficient number, since it is larger than the sum of its proper divisors (111208975831).

2557806443561 is a wasteful number, since it uses less digits than its factorization.

2557806443561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111208975830.

The product of its (nonzero) digits is 24192000, while the sum is 56.

The spelling of 2557806443561 in words is "two trillion, five hundred fifty-seven billion, eight hundred six million, four hundred forty-three thousand, five hundred sixty-one".