2556591 has 4 divisors (see below), whose sum is σ = 3408792. Its totient is φ = 1704392.

The previous prime is 2556577. The next prime is 2556607. The reversal of 2556591 is 1956552.

2556591 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.

It is a cyclic number.

It is not a de Polignac number, because 2556591 - 2⁵ = 2556559 is a prime.

It is a D-number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2556091) 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 in 3 ways as a sum of consecutive naturals, for example, 426096 + ... + 426101.

It is an arithmetic number, because the mean of its divisors is an integer number (852198).

2^2556591 is an apocalyptic number.

2556591 is a deficient number, since it is larger than the sum of its proper divisors (852201).

2556591 is an equidigital number, since it uses as much as digits as its factorization.

2556591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 852200.

The product of its digits is 13500, while the sum is 33.

The square root of 2556591 is about 1598.9343326103. The cubic root of 2556591 is about 136.7373268025.

It can be divided in two parts, 25 and 56591, that added together give a triangular number (56616 = T₃₃₆).

The spelling of 2556591 in words is "two million, five hundred fifty-six thousand, five hundred ninety-one".