31121331321 has 8 divisors (see below), whose sum is σ = 41508076320. Its totient is φ = 20741070272.

The previous prime is 31121331247. The next prime is 31121331323. The reversal of 31121331321 is 12313312113.

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 31121331321 - 2¹⁰ = 31121330297 is a prime.

It is not an unprimeable number, because it can be changed into a prime (31121331323) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1609776 + ... + 1628993.

It is an arithmetic number, because the mean of its divisors is an integer number (5188509540).

Almost surely, 2^31121331321 is an apocalyptic number.

It is an amenable number.

31121331321 is a deficient number, since it is larger than the sum of its proper divisors (10386744999).

31121331321 is a wasteful number, since it uses less digits than its factorization.

31121331321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3241975.

The product of its digits is 324, while the sum is 21.

Adding to 31121331321 its reverse (12313312113), we get a palindrome (43434643434).

The spelling of 31121331321 in words is "thirty-one billion, one hundred twenty-one million, three hundred thirty-one thousand, three hundred twenty-one".