63561 has 4 divisors (see below), whose sum is σ = 84752. Its totient is φ = 42372.

The previous prime is 63559. The next prime is 63577. The reversal of 63561 is 16536.

63561 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 semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 63561 - 2¹ = 63559 is a prime.

It is a D-number.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (63521) 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, 10591 + ... + 10596.

It is an arithmetic number, because the mean of its divisors is an integer number (21188).

2⁶³⁵⁶¹ is an apocalyptic number.

It is an amenable number.

63561 is a deficient number, since it is larger than the sum of its proper divisors (21191).

63561 is a wasteful number, since it uses less digits than its factorization.

63561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21190.

The product of its digits is 540, while the sum is 21.

The square root of 63561 is about 252.1130698714. The cubic root of 63561 is about 39.9083317504.

It can be divided in two parts, 635 and 61, that added together give a palindrome (696).

The spelling of 63561 in words is "sixty-three thousand, five hundred sixty-one".