21032311081 has 2 divisors, whose sum is σ = 21032311082. Its totient is φ = 21032311080.

The previous prime is 21032311067. The next prime is 21032311109. The reversal of 21032311081 is 18011323012.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20935485481 + 96825600 = 144691^2 + 9840^2 .

It is a cyclic number.

It is not a de Polignac number, because 21032311081 - 2⁵ = 21032311049 is a prime.

It is a super-3 number, since 3×21032311081³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not a weakly prime, because it can be changed into another prime (21032318081) 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, 10516155540 + 10516155541.

It is an arithmetic number, because the mean of its divisors is an integer number (10516155541).

Almost surely, 2^21032311081 is an apocalyptic number.

It is an amenable number.

21032311081 is a deficient number, since it is larger than the sum of its proper divisors (1).

21032311081 is an equidigital number, since it uses as much as digits as its factorization.

21032311081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 288, while the sum is 22.

Adding to 21032311081 its reverse (18011323012), we get a palindrome (39043634093).

The spelling of 21032311081 in words is "twenty-one billion, thirty-two million, three hundred eleven thousand, eighty-one".