31221321133 has 2 divisors, whose sum is σ = 31221321134. Its totient is φ = 31221321132.

The previous prime is 31221321077. The next prime is 31221321137. The reversal of 31221321133 is 33112312213.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 28217952324 + 3003368809 = 167982^2 + 54803^2 .

It is an emirp because it is prime and its reverse (33112312213) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31221321133 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31221321137) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15610660566 + 15610660567.

It is an arithmetic number, because the mean of its divisors is an integer number (15610660567).

Almost surely, 2^31221321133 is an apocalyptic number.

It is an amenable number.

31221321133 is a deficient number, since it is larger than the sum of its proper divisors (1).

31221321133 is an equidigital number, since it uses as much as digits as its factorization.

31221321133 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 648, while the sum is 22.

Adding to 31221321133 its reverse (33112312213), we get a palindrome (64333633346).

The spelling of 31221321133 in words is "thirty-one billion, two hundred twenty-one million, three hundred twenty-one thousand, one hundred thirty-three".