31121333321 has 16 divisors (see below), whose sum is σ = 33746634768. Its totient is φ = 28529280000.

The previous prime is 31121333303. The next prime is 31121333333. The reversal of 31121333321 is 12333312113.

It can be written as a sum of positive squares in 8 ways, for example, as 6791572921 + 24329760400 = 82411^2 + 155980^2 .

It is not a de Polignac number, because 31121333321 - 2²² = 31117139017 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31121335321) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6122501 + ... + 6127581.

It is an arithmetic number, because the mean of its divisors is an integer number (2109164673).

Almost surely, 2^31121333321 is an apocalyptic number.

It is an amenable number.

31121333321 is a deficient number, since it is larger than the sum of its proper divisors (2625301447).

31121333321 is a wasteful number, since it uses less digits than its factorization.

31121333321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8252.

The product of its digits is 972, while the sum is 23.

Adding to 31121333321 its reverse (12333312113), we get a palindrome (43454645434).

The spelling of 31121333321 in words is "thirty-one billion, one hundred twenty-one million, three hundred thirty-three thousand, three hundred twenty-one".