21200422081 has 2 divisors, whose sum is σ = 21200422082. Its totient is φ = 21200422080.

The previous prime is 21200422027. The next prime is 21200422153. The reversal of 21200422081 is 18022400212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12006680625 + 9193741456 = 109575^2 + 95884^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21200422081 is a prime.

It is a super-2 number, since 2×21200422081² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21200422181) 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, 10600211040 + 10600211041.

It is an arithmetic number, because the mean of its divisors is an integer number (10600211041).

Almost surely, 2^21200422081 is an apocalyptic number.

It is an amenable number.

21200422081 is a deficient number, since it is larger than the sum of its proper divisors (1).

21200422081 is an equidigital number, since it uses as much as digits as its factorization.

21200422081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 512, while the sum is 22.

Adding to 21200422081 its reverse (18022400212), we get a palindrome (39222822293).

The spelling of 21200422081 in words is "twenty-one billion, two hundred million, four hundred twenty-two thousand, eighty-one".