21321898889 has 2 divisors, whose sum is σ = 21321898890. Its totient is φ = 21321898888.

The previous prime is 21321898849. The next prime is 21321898891. The reversal of 21321898889 is 98889812312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11516938489 + 9804960400 = 107317^2 + 99020^2 .

It is a cyclic number.

It is not a de Polignac number, because 21321898889 - 2¹² = 21321894793 is a prime.

Together with 21321898891, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21321898849) 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, 10660949444 + 10660949445.

It is an arithmetic number, because the mean of its divisors is an integer number (10660949445).

Almost surely, 2^21321898889 is an apocalyptic number.

It is an amenable number.

21321898889 is a deficient number, since it is larger than the sum of its proper divisors (1).

21321898889 is an equidigital number, since it uses as much as digits as its factorization.

21321898889 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3981312, while the sum is 59.

The spelling of 21321898889 in words is "twenty-one billion, three hundred twenty-one million, eight hundred ninety-eight thousand, eight hundred eighty-nine".