21422399807789 has 2 divisors, whose sum is σ = 21422399807790. Its totient is φ = 21422399807788.

The previous prime is 21422399807723. The next prime is 21422399807791. The reversal of 21422399807789 is 98770899322412.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15200119005289 + 6222280802500 = 3898733^2 + 2494450^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21422399807789 is a prime.

Together with 21422399807791, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21422399807089) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10711199903894 + 10711199903895.

It is an arithmetic number, because the mean of its divisors is an integer number (10711199903895).

Almost surely, 2^{21422399807789} is an apocalyptic number.

It is an amenable number.

21422399807789 is a deficient number, since it is larger than the sum of its proper divisors (1).

21422399807789 is an equidigital number, since it uses as much as digits as its factorization.

21422399807789 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 219469824, while the sum is 71.

The spelling of 21422399807789 in words is "twenty-one trillion, four hundred twenty-two billion, three hundred ninety-nine million, eight hundred seven thousand, seven hundred eighty-nine".