8616561 has 4 divisors (see below), whose sum is σ = 11488752. Its totient is φ = 5744372.

The previous prime is 8616547. The next prime is 8616563. The reversal of 8616561 is 1656168.

8616561 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 a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 8616561 - 2¹¹ = 8614513 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (8616563) 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, 1436091 + ... + 1436096.

It is an arithmetic number, because the mean of its divisors is an integer number (2872188).

Almost surely, 2^8616561 is an apocalyptic number.

It is an amenable number.

8616561 is a deficient number, since it is larger than the sum of its proper divisors (2872191).

8616561 is a wasteful number, since it uses less digits than its factorization.

8616561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2872190.

The product of its digits is 8640, while the sum is 33.

The square root of 8616561 is about 2935.3979287313. The cubic root of 8616561 is about 205.0113894128.

The spelling of 8616561 in words is "eight million, six hundred sixteen thousand, five hundred sixty-one".