57561 has 8 divisors (see below), whose sum is σ = 87744. Its totient is φ = 32880.

The previous prime is 57559. The next prime is 57571. The reversal of 57561 is 16575.

57561 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 57561 - 2¹ = 57559 is a prime.

It is a Smith number, since the sum of its digits (24) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Curzon number.

57561 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (57571) 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, 1350 + ... + 1391.

It is an arithmetic number, because the mean of its divisors is an integer number (10968).

2⁵⁷⁵⁶¹ is an apocalyptic number.

It is an amenable number.

57561 is a deficient number, since it is larger than the sum of its proper divisors (30183).

57561 is a wasteful number, since it uses less digits than its factorization.

57561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2751.

The product of its digits is 1050, while the sum is 24.

The square root of 57561 is about 239.9187362421. The cubic root of 57561 is about 38.6108571927.

It can be divided in two parts, 575 and 61, that added together give a palindrome (636).

The spelling of 57561 in words is "fifty-seven thousand, five hundred sixty-one".