2561243 has 4 divisors (see below), whose sum is σ = 2564520. Its totient is φ = 2557968.

The previous prime is 2561239. The next prime is 2561261. The reversal of 2561243 is 3421652.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 2561243 - 2² = 2561239 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2561233) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 296 + ... + 2282.

It is an arithmetic number, because the mean of its divisors is an integer number (641130).

2^2561243 is an apocalyptic number.

2561243 is a deficient number, since it is larger than the sum of its proper divisors (3277).

2561243 is a wasteful number, since it uses less digits than its factorization.

2561243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3276.

The product of its digits is 1440, while the sum is 23.

The square root of 2561243 is about 1600.3883903603. The cubic root of 2561243 is about 136.8202127777.

Adding to 2561243 its reverse (3421652), we get a palindrome (5982895).

The spelling of 2561243 in words is "two million, five hundred sixty-one thousand, two hundred forty-three".