2561543 has 8 divisors (see below), whose sum is σ = 2764368. Its totient is φ = 2364544.

The previous prime is 2561527. The next prime is 2561549. The reversal of 2561543 is 3451652.

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 2561543 - 2⁴ = 2561527 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2561549) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 521 + ... + 2322.

It is an arithmetic number, because the mean of its divisors is an integer number (345546).

2^2561543 is an apocalyptic number.

2561543 is a deficient number, since it is larger than the sum of its proper divisors (202825).

2561543 is a wasteful number, since it uses less digits than its factorization.

2561543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2913.

The product of its digits is 3600, while the sum is 26.

The square root of 2561543 is about 1600.4821148641. The cubic root of 2561543 is about 136.8255545150.

The spelling of 2561543 in words is "two million, five hundred sixty-one thousand, five hundred forty-three".