31212100321 has 2 divisors, whose sum is σ = 31212100322. Its totient is φ = 31212100320.

The previous prime is 31212100307. The next prime is 31212100331. The reversal of 31212100321 is 12300121213.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 23390643600 + 7821456721 = 152940^2 + 88439^2 .

It is a cyclic number.

It is not a de Polignac number, because 31212100321 - 2¹⁵ = 31212067553 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 31212100295 and 31212100304.

It is not a weakly prime, because it can be changed into another prime (31212100331) 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, 15606050160 + 15606050161.

It is an arithmetic number, because the mean of its divisors is an integer number (15606050161).

Almost surely, 2^31212100321 is an apocalyptic number.

It is an amenable number.

31212100321 is a deficient number, since it is larger than the sum of its proper divisors (1).

31212100321 is an equidigital number, since it uses as much as digits as its factorization.

31212100321 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 31212100321 its reverse (12300121213), we get a palindrome (43512221534).

The spelling of 31212100321 in words is "thirty-one billion, two hundred twelve million, one hundred thousand, three hundred twenty-one".