36561 has 8 divisors (see below), whose sum is σ = 55744. Its totient is φ = 20880.

The previous prime is 36559. The next prime is 36563. The reversal of 36561 is 16563.

36561 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 an interprime number because it is at equal distance from previous prime (36559) and next prime (36563).

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

It is not a de Polignac number, because 36561 - 2¹ = 36559 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21), and also a Moran number because the ratio is a prime number: 1741 = 36561 / (3 + 6 + 5 + 6 + 1).

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

36561 is a lucky number.

It is a zygodrome in base 6.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 36561.

It is not an unprimeable number, because it can be changed into a prime (36563) 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, 850 + ... + 891.

It is an arithmetic number, because the mean of its divisors is an integer number (6968).

2³⁶⁵⁶¹ is an apocalyptic number.

It is an amenable number.

36561 is a deficient number, since it is larger than the sum of its proper divisors (19183).

36561 is a wasteful number, since it uses less digits than its factorization.

36561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1751.

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

The square root of 36561 is about 191.2093093968. The cubic root of 36561 is about 33.1899059651.

It can be divided in two parts, 3 and 6561, that multiplied together give a 9-th power (19683 = 3⁹).

The spelling of 36561 in words is "thirty-six thousand, five hundred sixty-one".