2556656789 has 4 divisors (see below), whose sum is σ = 2564025024. Its totient is φ = 2549288556.

The previous prime is 2556656783. The next prime is 2556656797. The reversal of 2556656789 is 9876566552.

2556656789 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 not a de Polignac number, because 2556656789 - 2⁸ = 2556656533 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2556656783) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3683597 + ... + 3684290.

It is an arithmetic number, because the mean of its divisors is an integer number (641006256).

Almost surely, 2^2556656789 is an apocalyptic number.

It is an amenable number.

2556656789 is a deficient number, since it is larger than the sum of its proper divisors (7368235).

2556656789 is an equidigital number, since it uses as much as digits as its factorization.

2556656789 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7368234.

The product of its digits is 27216000, while the sum is 59.

The square root of 2556656789 is about 50563.3937646594. The cubic root of 2556656789 is about 1367.3849968404.

The spelling of 2556656789 in words is "two billion, five hundred fifty-six million, six hundred fifty-six thousand, seven hundred eighty-nine".