2561003 has 4 divisors (see below), whose sum is σ = 2643648. Its totient is φ = 2478360.

The previous prime is 2560997. The next prime is 2561017. The reversal of 2561003 is 3001652.

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 2561003 - 2⁶ = 2560939 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2561023) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 41276 + ... + 41337.

It is an arithmetic number, because the mean of its divisors is an integer number (660912).

2^2561003 is an apocalyptic number.

2561003 is a deficient number, since it is larger than the sum of its proper divisors (82645).

2561003 is an equidigital number, since it uses as much as digits as its factorization.

2561003 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82644.

The product of its (nonzero) digits is 180, while the sum is 17.

The square root of 2561003 is about 1600.3134068051. The cubic root of 2561003 is about 136.8159390876.

Adding to 2561003 its reverse (3001652), we get a palindrome (5562655).

The spelling of 2561003 in words is "two million, five hundred sixty-one thousand, three".