221671 has 2 divisors, whose sum is σ = 221672. Its totient is φ = 221670.

The previous prime is 221659. The next prime is 221677. The reversal of 221671 is 176122.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 221671 - 2⁹ = 221159 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221677) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110835 + 110836.

It is an arithmetic number, because the mean of its divisors is an integer number (110836).

2²²¹⁶⁷¹ is an apocalyptic number.

221671 is a deficient number, since it is larger than the sum of its proper divisors (1).

221671 is an equidigital number, since it uses as much as digits as its factorization.

221671 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 168, while the sum is 19.

The square root of 221671 is about 470.8194983218. The cubic root of 221671 is about 60.5205630987.

Adding to 221671 its reverse (176122), we get a palindrome (397793).

The spelling of 221671 in words is "two hundred twenty-one thousand, six hundred seventy-one".