21911120281 has 2 divisors, whose sum is σ = 21911120282. Its totient is φ = 21911120280.

The previous prime is 21911120279. The next prime is 21911120381. The reversal of 21911120281 is 18202111912.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18203406400 + 3707713881 = 134920^2 + 60891^2 .

It is a cyclic number.

It is not a de Polignac number, because 21911120281 - 2¹ = 21911120279 is a prime.

It is a super-2 number, since 2×21911120281² (a number of 21 digits) contains 22 as substring.

Together with 21911120279, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21911120381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10955560140 + 10955560141.

It is an arithmetic number, because the mean of its divisors is an integer number (10955560141).

Almost surely, 2^21911120281 is an apocalyptic number.

It is an amenable number.

21911120281 is a deficient number, since it is larger than the sum of its proper divisors (1).

21911120281 is an equidigital number, since it uses as much as digits as its factorization.

21911120281 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 576, while the sum is 28.

The spelling of 21911120281 in words is "twenty-one billion, nine hundred eleven million, one hundred twenty thousand, two hundred eighty-one".