21422399207789 has 2 divisors, whose sum is σ = 21422399207790. Its totient is φ = 21422399207788.

The previous prime is 21422399207771. The next prime is 21422399207819. The reversal of 21422399207789 is 98770299322412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18441510632164 + 2980888575625 = 4294358^2 + 1726525^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21422399207789 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21422399807789) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10711199603894 + 10711199603895.

It is an arithmetic number, because the mean of its divisors is an integer number (10711199603895).

Almost surely, 2^{21422399207789} is an apocalyptic number.

It is an amenable number.

21422399207789 is a deficient number, since it is larger than the sum of its proper divisors (1).

21422399207789 is an equidigital number, since it uses as much as digits as its factorization.

21422399207789 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 54867456, while the sum is 65.

The spelling of 21422399207789 in words is "twenty-one trillion, four hundred twenty-two billion, three hundred ninety-nine million, two hundred seven thousand, seven hundred eighty-nine".