24561 has 6 divisors (see below), whose sum is σ = 35490. Its totient is φ = 16368.

The previous prime is 24551. The next prime is 24571. The reversal of 24561 is 16542.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (24551) and next prime (24571).

It can be written as a sum of positive squares in only one way, i.e., 24336 + 225 = 156^2 + 15^2 .

It is not a de Polignac number, because 24561 - 2⁹ = 24049 is a prime.

It is a Curzon number.

It is a plaindrome in base 12.

It is not an unprimeable number, because it can be changed into a prime (24551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1356 + ... + 1373.

It is an arithmetic number, because the mean of its divisors is an integer number (5915).

2²⁴⁵⁶¹ is an apocalyptic number.

It is an amenable number.

24561 is a deficient number, since it is larger than the sum of its proper divisors (10929).

24561 is a wasteful number, since it uses less digits than its factorization.

24561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2735 (or 2732 counting only the distinct ones).

The product of its digits is 240, while the sum is 18.

The square root of 24561 is about 156.7194946393. The cubic root of 24561 is about 29.0680131754.

It can be divided in two parts, 24 and 561, that added together give a palindrome (585).

The spelling of 24561 in words is "twenty-four thousand, five hundred sixty-one".