7171221 has 16 divisors (see below), whose sum is σ = 9820800. Its totient is φ = 4653120.

The previous prime is 7171217. The next prime is 7171223. The reversal of 7171221 is 1221717.

It is a happy number.

It is not a de Polignac number, because 7171221 - 2² = 7171217 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7171223) 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 in 15 ways as a sum of consecutive naturals, for example, 27136 + ... + 27398.

It is an arithmetic number, because the mean of its divisors is an integer number (613800).

Almost surely, 2^7171221 is an apocalyptic number.

It is an amenable number.

7171221 is a deficient number, since it is larger than the sum of its proper divisors (2649579).

7171221 is a wasteful number, since it uses less digits than its factorization.

7171221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 476.

The product of its digits is 196, while the sum is 21.

The square root of 7171221 is about 2677.9135534965. The cubic root of 7171221 is about 192.8402572714.

Adding to 7171221 its reverse (1221717), we get a palindrome (8392938).

The spelling of 7171221 in words is "seven million, one hundred seventy-one thousand, two hundred twenty-one".