8642561 has 4 divisors (see below), whose sum is σ = 8692692. Its totient is φ = 8592432.

The previous prime is 8642533. The next prime is 8642567. The reversal of 8642561 is 1652468.

8642561 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 5290000 + 3352561 = 2300^2 + 1831^2 .

It is a cyclic number.

It is not a de Polignac number, because 8642561 - 2¹⁸ = 8380417 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (8642567) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 24806 + ... + 25151.

It is an arithmetic number, because the mean of its divisors is an integer number (2173173).

It is a Proth number, since it is equal to 1055 ⋅ 2¹³ + 1 and 1055 < 2¹³.

Almost surely, 2^8642561 is an apocalyptic number.

It is an amenable number.

8642561 is a deficient number, since it is larger than the sum of its proper divisors (50131).

8642561 is a wasteful number, since it uses less digits than its factorization.

8642561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50130.

The product of its digits is 11520, while the sum is 32.

The square root of 8642561 is about 2939.8232940094. The cubic root of 8642561 is about 205.2173858965.

The spelling of 8642561 in words is "eight million, six hundred forty-two thousand, five hundred sixty-one".