30561 has 8 divisors (see below), whose sum is σ = 41664. Its totient is φ = 19920.

The previous prime is 30559. The next prime is 30577. The reversal of 30561 is 16503.

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

It is not a de Polignac number, because 30561 - 2¹ = 30559 is a prime.

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

It is a nialpdrome in base 16.

It is a self number, because there is not a number n which added to its sum of digits gives 30561.

It is not an unprimeable number, because it can be changed into a prime (30161) 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, 100 + ... + 266.

It is an arithmetic number, because the mean of its divisors is an integer number (5208).

2³⁰⁵⁶¹ is an apocalyptic number.

It is an amenable number.

30561 is a deficient number, since it is larger than the sum of its proper divisors (11103).

30561 is a wasteful number, since it uses less digits than its factorization.

30561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 231.

The product of its (nonzero) digits is 90, while the sum is 15.

The square root of 30561 is about 174.8170472237. The cubic root of 30561 is about 31.2648143094.

The spelling of 30561 in words is "thirty thousand, five hundred sixty-one".