2561705 has 8 divisors (see below), whose sum is σ = 3098304. Its totient is φ = 2033200.

The previous prime is 2561683. The next prime is 2561723. The reversal of 2561705 is 5071652.

2561705 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-2561705 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 1301 + ... + 2610.

It is an arithmetic number, because the mean of its divisors is an integer number (387288).

2^2561705 is an apocalyptic number.

It is an amenable number.

2561705 is a deficient number, since it is larger than the sum of its proper divisors (536599).

2561705 is a wasteful number, since it uses less digits than its factorization.

2561705 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4047.

The product of its (nonzero) digits is 2100, while the sum is 26.

The square root of 2561705 is about 1600.5327238142. The cubic root of 2561705 is about 136.8284388797.

The spelling of 2561705 in words is "two million, five hundred sixty-one thousand, seven hundred five".