331221 has 8 divisors (see below), whose sum is σ = 481824. Its totient is φ = 200720.

The previous prime is 331217. The next prime is 331231. The reversal of 331221 is 122133.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 331221 - 2² = 331217 is a prime.

It is a Curzon number.

331221 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 331197 and 331206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (331231) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4986 + ... + 5051.

It is an arithmetic number, because the mean of its divisors is an integer number (60228).

2³³¹²²¹ is an apocalyptic number.

It is an amenable number.

331221 is a deficient number, since it is larger than the sum of its proper divisors (150603).

331221 is a wasteful number, since it uses less digits than its factorization.

331221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10051.

The product of its digits is 36, while the sum is 12.

The square root of 331221 is about 575.5180275196. The cubic root of 331221 is about 69.1893559536.

Adding to 331221 its reverse (122133), we get a palindrome (453354).

It can be divided in two parts, 3312 and 21, that added together give a palindrome (3333).

The spelling of 331221 in words is "three hundred thirty-one thousand, two hundred twenty-one".