221071 has 2 divisors, whose sum is σ = 221072. Its totient is φ = 221070.

The previous prime is 221069. The next prime is 221077. The reversal of 221071 is 170122.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 221071 - 2¹ = 221069 is a prime.

Together with 221069, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221077) 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, 110535 + 110536.

It is an arithmetic number, because the mean of its divisors is an integer number (110536).

2²²¹⁰⁷¹ is an apocalyptic number.

221071 is a deficient number, since it is larger than the sum of its proper divisors (1).

221071 is an equidigital number, since it uses as much as digits as its factorization.

221071 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 28, while the sum is 13.

The square root of 221071 is about 470.1818797019. The cubic root of 221071 is about 60.4659098068.

Adding to 221071 its reverse (170122), we get a palindrome (391193).

The spelling of 221071 in words is "two hundred twenty-one thousand, seventy-one", and thus it is an iban number.