31032011221 has 2 divisors, whose sum is σ = 31032011222. Its totient is φ = 31032011220.

The previous prime is 31032011201. The next prime is 31032011299. The reversal of 31032011221 is 12211023013.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 24238130596 + 6793880625 = 155686^2 + 82425^2 .

It is a cyclic number.

It is not a de Polignac number, because 31032011221 - 2¹⁹ = 31031486933 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 31032011195 and 31032011204.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31032011201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15516005610 + 15516005611.

It is an arithmetic number, because the mean of its divisors is an integer number (15516005611).

Almost surely, 2^31032011221 is an apocalyptic number.

It is an amenable number.

31032011221 is a deficient number, since it is larger than the sum of its proper divisors (1).

31032011221 is an equidigital number, since it uses as much as digits as its factorization.

31032011221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72, while the sum is 16.

Adding to 31032011221 its reverse (12211023013), we get a palindrome (43243034234).

The spelling of 31032011221 in words is "thirty-one billion, thirty-two million, eleven thousand, two hundred twenty-one".