2561005 has 8 divisors (see below), whose sum is σ = 3086712. Its totient is φ = 2039808.

The previous prime is 2560997. The next prime is 2561017. The reversal of 2561005 is 5001652.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 1247689 + 1313316 = 1117^2 + 1146^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 2561005 - 2³ = 2560997 is a prime.

It is a super-2 number, since 2×2561005² = 13117493220050, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 289 + ... + 2281.

It is an arithmetic number, because the mean of its divisors is an integer number (385839).

2^2561005 is an apocalyptic number.

It is an amenable number.

2561005 is a deficient number, since it is larger than the sum of its proper divisors (525707).

2561005 is a wasteful number, since it uses less digits than its factorization.

2561005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2255.

The product of its (nonzero) digits is 300, while the sum is 19.

The square root of 2561005 is about 1600.3140316825. The cubic root of 2561005 is about 136.8159747028.

Adding to 2561005 its reverse (5001652), we get a palindrome (7562657).

The spelling of 2561005 in words is "two million, five hundred sixty-one thousand, five".