9872561 has 4 divisors (see below), whose sum is σ = 9885300. Its totient is φ = 9859824.

The previous prime is 9872521. The next prime is 9872567. The reversal of 9872561 is 1652789.

9872561 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4490161 + 5382400 = 2119^2 + 2320^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9872561 is a prime.

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

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9872567) 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 3 ways as a sum of consecutive naturals, for example, 5126 + ... + 6783.

It is an arithmetic number, because the mean of its divisors is an integer number (2471325).

Almost surely, 2^9872561 is an apocalyptic number.

It is an amenable number.

9872561 is a deficient number, since it is larger than the sum of its proper divisors (12739).

9872561 is a wasteful number, since it uses less digits than its factorization.

9872561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12738.

The product of its digits is 30240, while the sum is 38.

The square root of 9872561 is about 3142.0631756857. The cubic root of 9872561 is about 214.5243568424.

The spelling of 9872561 in words is "nine million, eight hundred seventy-two thousand, five hundred sixty-one".