8220561 has 4 divisors (see below), whose sum is σ = 10960752. Its totient is φ = 5480372.

The previous prime is 8220557. The next prime is 8220577. The reversal of 8220561 is 1650228.

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 8220561 - 2² = 8220557 is a prime.

8220561 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (8220551) 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, 1370091 + ... + 1370096.

It is an arithmetic number, because the mean of its divisors is an integer number (2740188).

Almost surely, 2^8220561 is an apocalyptic number.

It is an amenable number.

8220561 is a deficient number, since it is larger than the sum of its proper divisors (2740191).

8220561 is a wasteful number, since it uses less digits than its factorization.

8220561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2740190.

The product of its (nonzero) digits is 960, while the sum is 24.

The square root of 8220561 is about 2867.1520713070. The cubic root of 8220561 is about 201.8213710197.

Adding to 8220561 its reverse (1650228), we get a palindrome (9870789).

The spelling of 8220561 in words is "eight million, two hundred twenty thousand, five hundred sixty-one".