31203123201221 has 2 divisors, whose sum is σ = 31203123201222. Its totient is φ = 31203123201220.

The previous prime is 31203123201193. The next prime is 31203123201233. The reversal of 31203123201221 is 12210232130213.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20041603936225 + 11161519264996 = 4476785^2 + 3340886^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31203123201221 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31203123201241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15601561600610 + 15601561600611.

It is an arithmetic number, because the mean of its divisors is an integer number (15601561600611).

Almost surely, 2^{31203123201221} is an apocalyptic number.

It is an amenable number.

31203123201221 is a deficient number, since it is larger than the sum of its proper divisors (1).

31203123201221 is an equidigital number, since it uses as much as digits as its factorization.

31203123201221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 864, while the sum is 23.

Adding to 31203123201221 its reverse (12210232130213), we get a palindrome (43413355331434).

The spelling of 31203123201221 in words is "thirty-one trillion, two hundred three billion, one hundred twenty-three million, two hundred one thousand, two hundred twenty-one".