31321321121 has 4 divisors (see below), whose sum is σ = 31322787972. Its totient is φ = 31319854272.

The previous prime is 31321321117. The next prime is 31321321123. The reversal of 31321321121 is 12112312313.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12112312313 = 2029 ⋅5969597.

It can be written as a sum of positive squares in 2 ways, for example, as 25379994721 + 5941326400 = 159311^2 + 77080^2 .

It is a cyclic number.

It is not a de Polignac number, because 31321321121 - 2² = 31321321117 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31321321093 and 31321321102.

It is not an unprimeable number, because it can be changed into a prime (31321321123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 700916 + ... + 744261.

It is an arithmetic number, because the mean of its divisors is an integer number (7830696993).

Almost surely, 2^31321321121 is an apocalyptic number.

It is an amenable number.

31321321121 is a deficient number, since it is larger than the sum of its proper divisors (1466851).

31321321121 is a wasteful number, since it uses less digits than its factorization.

31321321121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1466850.

The product of its digits is 216, while the sum is 20.

Adding to 31321321121 its reverse (12112312313), we get a palindrome (43433633434).

The spelling of 31321321121 in words is "thirty-one billion, three hundred twenty-one million, three hundred twenty-one thousand, one hundred twenty-one".