2561823 has 24 divisors (see below), whose sum is σ = 4090320. Its totient is φ = 1532160.

The previous prime is 2561821. The next prime is 2561833. The reversal of 2561823 is 3281652.

2561823 is a `hidden beast` number, since 25 + 618 + 23 = 666.

It is not a de Polignac number, because 2561823 - 2¹ = 2561821 is a prime.

It is a d-powerful number, because it can be written as 2² + 5⁸ + 6⁵ + 1 + 8⁷ + 2¹⁶ + 3⁶ .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2561821) 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 23 ways as a sum of consecutive naturals, for example, 11073 + ... + 11301.

It is an arithmetic number, because the mean of its divisors is an integer number (170430).

2^2561823 is an apocalyptic number.

2561823 is a deficient number, since it is larger than the sum of its proper divisors (1528497).

2561823 is a wasteful number, since it uses less digits than its factorization.

2561823 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 359 (or 356 counting only the distinct ones).

The product of its digits is 2880, while the sum is 27.

The square root of 2561823 is about 1600.5695861161. The cubic root of 2561823 is about 136.8305397601.

The spelling of 2561823 in words is "two million, five hundred sixty-one thousand, eight hundred twenty-three".