8638561 has 4 divisors (see below), whose sum is σ = 8644500. Its totient is φ = 8632624.

The previous prime is 8638543. The next prime is 8638583. The reversal of 8638561 is 1658368.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 8208225 + 430336 = 2865^2 + 656^2 .

It is a cyclic number.

It is not a de Polignac number, because 8638561 - 2¹¹ = 8636513 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 8638561.

It is not an unprimeable number, because it can be changed into a prime (8638061) 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, 855 + ... + 4243.

It is an arithmetic number, because the mean of its divisors is an integer number (2161125).

Almost surely, 2^8638561 is an apocalyptic number.

It is an amenable number.

8638561 is a deficient number, since it is larger than the sum of its proper divisors (5939).

8638561 is a wasteful number, since it uses less digits than its factorization.

8638561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5938.

The product of its digits is 34560, while the sum is 37.

The square root of 8638561 is about 2939.1429022761. The cubic root of 8638561 is about 205.1857210456.

The spelling of 8638561 in words is "eight million, six hundred thirty-eight thousand, five hundred sixty-one".