21400443211 has 6 divisors (see below), whose sum is σ = 24894393180. Its totient is φ = 18343236996.

The previous prime is 21400443143. The next prime is 21400443221. The reversal of 21400443211 is 11234400412.

It is a happy number.

It is not a de Polignac number, because 21400443211 - 2¹⁷ = 21400312139 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21400443221) 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 in 5 ways as a sum of consecutive naturals, for example, 218371821 + ... + 218371918.

It is an arithmetic number, because the mean of its divisors is an integer number (4149065530).

Almost surely, 2^21400443211 is an apocalyptic number.

21400443211 is a deficient number, since it is larger than the sum of its proper divisors (3493949969).

21400443211 is an equidigital number, since it uses as much as digits as its factorization.

21400443211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 436743753 (or 436743746 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 22.

Adding to 21400443211 its reverse (11234400412), we get a palindrome (32634843623).

The spelling of 21400443211 in words is "twenty-one billion, four hundred million, four hundred forty-three thousand, two hundred eleven".