105561221 has 2 divisors, whose sum is σ = 105561222. Its totient is φ = 105561220.

The previous prime is 105561199. The next prime is 105561223. The reversal of 105561221 is 122165501.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 99002500 + 6558721 = 9950^2 + 2561^2 .

It is a cyclic number.

It is not a de Polignac number, because 105561221 - 2¹⁰ = 105560197 is a prime.

It is a super-2 number, since 2×105561221² = 22286342758021682, which contains 22 as substring.

Together with 105561223, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (105561223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 52780610 + 52780611.

It is an arithmetic number, because the mean of its divisors is an integer number (52780611).

Almost surely, 2^105561221 is an apocalyptic number.

It is an amenable number.

105561221 is a deficient number, since it is larger than the sum of its proper divisors (1).

105561221 is an equidigital number, since it uses as much as digits as its factorization.

105561221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 600, while the sum is 23.

The square root of 105561221 is about 10274.2990515168. The cubic root of 105561221 is about 472.6084347495.

The spelling of 105561221 in words is "one hundred five million, five hundred sixty-one thousand, two hundred twenty-one".