31133432221 has 2 divisors, whose sum is σ = 31133432222. Its totient is φ = 31133432220.

The previous prime is 31133432207. The next prime is 31133432227. The reversal of 31133432221 is 12223433113.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 30490048996 + 643383225 = 174614^2 + 25365^2 .

It is a cyclic number.

It is not a de Polignac number, because 31133432221 - 2¹¹ = 31133430173 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31133432227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15566716110 + 15566716111.

It is an arithmetic number, because the mean of its divisors is an integer number (15566716111).

Almost surely, 2^31133432221 is an apocalyptic number.

It is an amenable number.

31133432221 is a deficient number, since it is larger than the sum of its proper divisors (1).

31133432221 is an equidigital number, since it uses as much as digits as its factorization.

31133432221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2592, while the sum is 25.

Adding to 31133432221 its reverse (12223433113), we get a palindrome (43356865334).

The spelling of 31133432221 in words is "thirty-one billion, one hundred thirty-three million, four hundred thirty-two thousand, two hundred twenty-one".