20559817189 has 2 divisors, whose sum is σ = 20559817190. Its totient is φ = 20559817188.

The previous prime is 20559817171. The next prime is 20559817249. The reversal of 20559817189 is 98171895502.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18132776964 + 2427040225 = 134658^2 + 49265^2 .

It is a cyclic number.

It is not a de Polignac number, because 20559817189 - 2¹¹ = 20559815141 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20559817589) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10279908594 + 10279908595.

It is an arithmetic number, because the mean of its divisors is an integer number (10279908595).

Almost surely, 2^20559817189 is an apocalyptic number.

It is an amenable number.

20559817189 is a deficient number, since it is larger than the sum of its proper divisors (1).

20559817189 is an equidigital number, since it uses as much as digits as its factorization.

20559817189 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1814400, while the sum is 55.

The spelling of 20559817189 in words is "twenty billion, five hundred fifty-nine million, eight hundred seventeen thousand, one hundred eighty-nine".