31031221133 has 48 divisors (see below), whose sum is σ = 36830732400. Its totient is φ = 26029301760.

The previous prime is 31031221129. The next prime is 31031221157. The reversal of 31031221133 is 33112213013.

It can be written as a sum of positive squares in 8 ways, for example, as 14131741129 + 16899480004 = 118877^2 + 129998^2 .

It is not a de Polignac number, because 31031221133 - 2² = 31031221129 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31031221033) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 29581193 + ... + 29582241.

It is an arithmetic number, because the mean of its divisors is an integer number (767306925).

Almost surely, 2^31031221133 is an apocalyptic number.

It is an amenable number.

31031221133 is a deficient number, since it is larger than the sum of its proper divisors (5799511267).

31031221133 is a wasteful number, since it uses less digits than its factorization.

31031221133 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1358 (or 1347 counting only the distinct ones).

The product of its (nonzero) digits is 324, while the sum is 20.

Adding to 31031221133 its reverse (33112213013), we get a palindrome (64143434146).

The spelling of 31031221133 in words is "thirty-one billion, thirty-one million, two hundred twenty-one thousand, one hundred thirty-three".