13171221 has 32 divisors (see below), whose sum is σ = 22471680. Its totient is φ = 7468848.

The previous prime is 13171183. The next prime is 13171241. The reversal of 13171221 is 12217131.

It is a happy number.

13171221 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 13171221 - 2¹¹ = 13169173 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 13171194 and 13171203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13171241) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 42750 + ... + 43056.

It is an arithmetic number, because the mean of its divisors is an integer number (702240).

Almost surely, 2^13171221 is an apocalyptic number.

It is an amenable number.

13171221 is a deficient number, since it is larger than the sum of its proper divisors (9300459).

13171221 is a wasteful number, since it uses less digits than its factorization.

13171221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 550 (or 544 counting only the distinct ones).

The product of its digits is 84, while the sum is 18.

The square root of 13171221 is about 3629.2176842951. The cubic root of 13171221 is about 236.1612717952.

Adding to 13171221 its reverse (12217131), we get a palindrome (25388352).

The spelling of 13171221 in words is "thirteen million, one hundred seventy-one thousand, two hundred twenty-one".