561100221 has 12 divisors (see below), whose sum is σ = 884158080. Its totient is φ = 340060680.

The previous prime is 561100219. The next prime is 561100223. The reversal of 561100221 is 122001165.

561100221 is a `hidden beast` number, since 561 + 100 + 2 + 2 + 1 = 666.

It is an interprime number because it is at equal distance from previous prime (561100219) and next prime (561100223).

It is not a de Polignac number, because 561100221 - 2¹ = 561100219 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 561100194 and 561100203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (561100223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2833741 + ... + 2833938.

It is an arithmetic number, because the mean of its divisors is an integer number (73679840).

Almost surely, 2^561100221 is an apocalyptic number.

It is an amenable number.

561100221 is a deficient number, since it is larger than the sum of its proper divisors (323057859).

561100221 is a wasteful number, since it uses less digits than its factorization.

561100221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5667696 (or 5667693 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 18.

The square root of 561100221 is about 23687.5541371413. The cubic root of 561100221 is about 824.7965073869.

Adding to 561100221 its reverse (122001165), we get a palindrome (683101386).

The spelling of 561100221 in words is "five hundred sixty-one million, one hundred thousand, two hundred twenty-one".