221173109 has 2 divisors, whose sum is σ = 221173110. Its totient is φ = 221173108.

The previous prime is 221173063. The next prime is 221173151. The reversal of 221173109 is 901371122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 159314884 + 61858225 = 12622^2 + 7865^2 .

It is a cyclic number.

It is not a de Polignac number, because 221173109 - 2²⁰ = 220124533 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221173159) 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 as a sum of consecutive naturals, namely, 110586554 + 110586555.

It is an arithmetic number, because the mean of its divisors is an integer number (110586555).

Almost surely, 2^221173109 is an apocalyptic number.

It is an amenable number.

221173109 is a deficient number, since it is larger than the sum of its proper divisors (1).

221173109 is an equidigital number, since it uses as much as digits as its factorization.

221173109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 756, while the sum is 26.

The square root of 221173109 is about 14871.8898933525. The cubic root of 221173109 is about 604.7521777159.

The spelling of 221173109 in words is "two hundred twenty-one million, one hundred seventy-three thousand, one hundred nine".