331533221 has 8 divisors (see below), whose sum is σ = 334253304. Its totient is φ = 328822720.

The previous prime is 331533211. The next prime is 331533229. The reversal of 331533221 is 122335133.

It can be written as a sum of positive squares in 4 ways, for example, as 81450625 + 250082596 = 9025^2 + 15814^2 .

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 331533221 - 2⁶ = 331533157 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (331533229) 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, 77675 + ... + 81831.

It is an arithmetic number, because the mean of its divisors is an integer number (41781663).

Almost surely, 2^331533221 is an apocalyptic number.

It is an amenable number.

331533221 is a deficient number, since it is larger than the sum of its proper divisors (2720083).

331533221 is a wasteful number, since it uses less digits than its factorization.

331533221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4791.

The product of its digits is 1620, while the sum is 23.

The square root of 331533221 is about 18208.0537400349. The cubic root of 331533221 is about 692.1108926332.

Adding to 331533221 its reverse (122335133), we get a palindrome (453868354).

The spelling of 331533221 in words is "three hundred thirty-one million, five hundred thirty-three thousand, two hundred twenty-one".