221644117 has 2 divisors, whose sum is σ = 221644118. Its totient is φ = 221644116.

The previous prime is 221644103. The next prime is 221644121. The reversal of 221644117 is 711446122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 196953156 + 24690961 = 14034^2 + 4969^2 .

It is a cyclic number.

It is not a de Polignac number, because 221644117 - 2¹⁵ = 221611349 is a prime.

It is a super-2 number, since 2×221644117² = 98252229201419378, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221644417) by changing a digit.

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

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110822058 + 110822059.

It is an arithmetic number, because the mean of its divisors is an integer number (110822059).

Almost surely, 2^221644117 is an apocalyptic number.

It is an amenable number.

221644117 is a deficient number, since it is larger than the sum of its proper divisors (1).

221644117 is an equidigital number, since it uses as much as digits as its factorization.

221644117 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2688, while the sum is 28.

The square root of 221644117 is about 14887.7169841450. The cubic root of 221644117 is about 605.1811646969.

It can be divided in two parts, 2 and 21644117, that multiplied together give a palindrome (43288234).

The spelling of 221644117 in words is "two hundred twenty-one million, six hundred forty-four thousand, one hundred seventeen".