21073008637789 has 2 divisors, whose sum is σ = 21073008637790. Its totient is φ = 21073008637788.

The previous prime is 21073008637739. The next prime is 21073008637799. The reversal of 21073008637789 is 98773680037012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14863592540889 + 6209416096900 = 3855333^2 + 2491870^2 .

It is a cyclic number.

It is not a de Polignac number, because 21073008637789 - 2¹¹ = 21073008635741 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21073008637739) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10536504318894 + 10536504318895.

It is an arithmetic number, because the mean of its divisors is an integer number (10536504318895).

Almost surely, 2^{21073008637789} is an apocalyptic number.

It is an amenable number.

21073008637789 is a deficient number, since it is larger than the sum of its proper divisors (1).

21073008637789 is an equidigital number, since it uses as much as digits as its factorization.

21073008637789 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 21337344, while the sum is 61.

The spelling of 21073008637789 in words is "twenty-one trillion, seventy-three billion, eight million, six hundred thirty-seven thousand, seven hundred eighty-nine".