2561656 has 24 divisors (see below), whose sum is σ = 5074920. Its totient is φ = 1212048.

The previous prime is 2561653. The next prime is 2561659. The reversal of 2561656 is 6561652.

2561656 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (2561653) and next prime (2561659).

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2561651) 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 5 ways as a sum of consecutive naturals, for example, 2445 + ... + 3331.

It is an arithmetic number, because the mean of its divisors is an integer number (211455).

2^2561656 is an apocalyptic number.

It is an amenable number.

2561656 is a deficient number, since it is larger than the sum of its proper divisors (2513264).

2561656 is a wasteful number, since it uses less digits than its factorization.

2561656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 931 (or 908 counting only the distinct ones).

The product of its digits is 10800, while the sum is 31.

The square root of 2561656 is about 1600.5174163376. The cubic root of 2561656 is about 136.8275664612.

The spelling of 2561656 in words is "two million, five hundred sixty-one thousand, six hundred fifty-six".