20208866789 has 2 divisors, whose sum is σ = 20208866790. Its totient is φ = 20208866788.

The previous prime is 20208866771. The next prime is 20208866819. The reversal of 20208866789 is 98766880202.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11232820225 + 8976046564 = 105985^2 + 94742^2 .

It is a cyclic number.

It is not a de Polignac number, because 20208866789 - 2²⁴ = 20192089573 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20208866189) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10104433394 + 10104433395.

It is an arithmetic number, because the mean of its divisors is an integer number (10104433395).

Almost surely, 2^20208866789 is an apocalyptic number.

It is an amenable number.

20208866789 is a deficient number, since it is larger than the sum of its proper divisors (1).

20208866789 is an equidigital number, since it uses as much as digits as its factorization.

20208866789 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4644864, while the sum is 56.

The spelling of 20208866789 in words is "twenty billion, two hundred eight million, eight hundred sixty-six thousand, seven hundred eighty-nine".