20321212081 has 2 divisors, whose sum is σ = 20321212082. Its totient is φ = 20321212080.

The previous prime is 20321212073. The next prime is 20321212127. The reversal of 20321212081 is 18021212302.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19970211856 + 351000225 = 141316^2 + 18735^2 .

It is a cyclic number.

It is not a de Polignac number, because 20321212081 - 2³ = 20321212073 is a prime.

It is a super-2 number, since 2×20321212081² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20321212781) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10160606040 + 10160606041.

It is an arithmetic number, because the mean of its divisors is an integer number (10160606041).

Almost surely, 2^20321212081 is an apocalyptic number.

It is an amenable number.

20321212081 is a deficient number, since it is larger than the sum of its proper divisors (1).

20321212081 is an equidigital number, since it uses as much as digits as its factorization.

20321212081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 384, while the sum is 22.

Adding to 20321212081 its reverse (18021212302), we get a palindrome (38342424383).

The spelling of 20321212081 in words is "twenty billion, three hundred twenty-one million, two hundred twelve thousand, eighty-one".