31233201221 has 2 divisors, whose sum is σ = 31233201222. Its totient is φ = 31233201220.

The previous prime is 31233201211. The next prime is 31233201229. The reversal of 31233201221 is 12210233213.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 26736828196 + 4496373025 = 163514^2 + 67055^2 .

It is a cyclic number.

It is not a de Polignac number, because 31233201221 - 2⁶ = 31233201157 is a prime.

It is a super-2 number, since 2×31233201221² (a number of 22 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 31233201193 and 31233201202.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31233201229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15616600610 + 15616600611.

It is an arithmetic number, because the mean of its divisors is an integer number (15616600611).

Almost surely, 2^31233201221 is an apocalyptic number.

It is an amenable number.

31233201221 is a deficient number, since it is larger than the sum of its proper divisors (1).

31233201221 is an equidigital number, since it uses as much as digits as its factorization.

31233201221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 432, while the sum is 20.

Adding to 31233201221 its reverse (12210233213), we get a palindrome (43443434434).

The spelling of 31233201221 in words is "thirty-one billion, two hundred thirty-three million, two hundred one thousand, two hundred twenty-one".