71221 has 4 divisors (see below), whose sum is σ = 72352. Its totient is φ = 70092.

The previous prime is 71209. The next prime is 71233. The reversal of 71221 is 12217.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12217 = 19 ⋅643.

It is an interprime number because it is at equal distance from previous prime (71209) and next prime (71233).

It is a cyclic number.

It is not a de Polignac number, because 71221 - 2⁹ = 70709 is a prime.

It is a Duffinian number.

71221 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71261) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 465 + ... + 598.

It is an arithmetic number, because the mean of its divisors is an integer number (18088).

2⁷¹²²¹ is an apocalyptic number.

It is an amenable number.

71221 is a deficient number, since it is larger than the sum of its proper divisors (1131).

71221 is a wasteful number, since it uses less digits than its factorization.

71221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1130.

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

The square root of 71221 is about 266.8726287951. The cubic root of 71221 is about 41.4510964083.

Adding to 71221 its reverse (12217), we get a palindrome (83438).

It can be divided in two parts, 71 and 221, that added together give a palindrome (292).

The spelling of 71221 in words is "seventy-one thousand, two hundred twenty-one", and thus it is an iban number.