331121321 has 4 divisors (see below), whose sum is σ = 333230532. Its totient is φ = 329012112.

The previous prime is 331121299. The next prime is 331121347. The reversal of 331121321 is 123121133.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 213160000 + 117961321 = 14600^2 + 10861^2 .

It is a cyclic number.

It is not a de Polignac number, because 331121321 - 2¹⁰ = 331120297 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 331121321.

It is not an unprimeable number, because it can be changed into a prime (331121381) 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, 1054370 + ... + 1054683.

It is an arithmetic number, because the mean of its divisors is an integer number (83307633).

Almost surely, 2^331121321 is an apocalyptic number.

It is an amenable number.

331121321 is a deficient number, since it is larger than the sum of its proper divisors (2109211).

331121321 is a wasteful number, since it uses less digits than its factorization.

331121321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2109210.

The product of its digits is 108, while the sum is 17.

The square root of 331121321 is about 18196.7392958189. The cubic root of 331121321 is about 691.8241454815.

Adding to 331121321 its reverse (123121133), we get a palindrome (454242454).

The spelling of 331121321 in words is "three hundred thirty-one million, one hundred twenty-one thousand, three hundred twenty-one".