31133021221 has 8 divisors (see below), whose sum is σ = 31897505304. Its totient is φ = 30368782080.

The previous prime is 31133021189. The next prime is 31133021233. The reversal of 31133021221 is 12212033113.

It can be written as a sum of positive squares in 4 ways, for example, as 1598880196 + 29534141025 = 39986^2 + 171855^2 .

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 31133021221 - 2⁵ = 31133021189 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31133021291) 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 7 ways as a sum of consecutive naturals, for example, 210735 + ... + 326611.

It is an arithmetic number, because the mean of its divisors is an integer number (3987188163).

Almost surely, 2^31133021221 is an apocalyptic number.

It is an amenable number.

31133021221 is a deficient number, since it is larger than the sum of its proper divisors (764484083).

31133021221 is a wasteful number, since it uses less digits than its factorization.

31133021221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 122471.

The product of its (nonzero) digits is 216, while the sum is 19.

Adding to 31133021221 its reverse (12212033113), we get a palindrome (43345054334).

The spelling of 31133021221 in words is "thirty-one billion, one hundred thirty-three million, twenty-one thousand, two hundred twenty-one".