221571 has 12 divisors (see below), whose sum is σ = 365872. Its totient is φ = 126576.

The previous prime is 221567. The next prime is 221581. The reversal of 221571 is 175122.

It is not a de Polignac number, because 221571 - 2² = 221567 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221581) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1696 + ... + 1821.

2²²¹⁵⁷¹ is an apocalyptic number.

221571 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

221571 is a deficient number, since it is larger than the sum of its proper divisors (144301).

221571 is a wasteful number, since it uses less digits than its factorization.

221571 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3530 (or 3527 counting only the distinct ones).

The product of its digits is 140, while the sum is 18.

The square root of 221571 is about 470.7132885314. The cubic root of 221571 is about 60.5114610712.

Adding to 221571 its reverse (175122), we get a palindrome (396693).

The spelling of 221571 in words is "two hundred twenty-one thousand, five hundred seventy-one".