31233221021 has 8 divisors (see below), whose sum is σ = 31907862360. Its totient is φ = 30561740352.

The previous prime is 31233220969. The next prime is 31233221023. The reversal of 31233221021 is 12012233213.

It can be written as a sum of positive squares in 4 ways, for example, as 11817864100 + 19415356921 = 108710^2 + 139339^2 .

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 31233221021 - 2³⁰ = 30159479197 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31233220984 and 31233221002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31233221023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 770186 + ... + 809723.

It is an arithmetic number, because the mean of its divisors is an integer number (3988482795).

Almost surely, 2^31233221021 is an apocalyptic number.

It is an amenable number.

31233221021 is a deficient number, since it is larger than the sum of its proper divisors (674641339).

31233221021 is a wasteful number, since it uses less digits than its factorization.

31233221021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1580335.

The product of its (nonzero) digits is 432, while the sum is 20.

Adding to 31233221021 its reverse (12012233213), we get a palindrome (43245454234).

The spelling of 31233221021 in words is "thirty-one billion, two hundred thirty-three million, two hundred twenty-one thousand, twenty-one".