20990846189 has 2 divisors, whose sum is σ = 20990846190. Its totient is φ = 20990846188.

The previous prime is 20990846143. The next prime is 20990846197. The reversal of 20990846189 is 98164809902.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20333334025 + 657512164 = 142595^2 + 25642^2 .

It is a cyclic number.

It is not a de Polignac number, because 20990846189 - 2⁸ = 20990845933 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20990842189) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10495423094 + 10495423095.

It is an arithmetic number, because the mean of its divisors is an integer number (10495423095).

Almost surely, 2^20990846189 is an apocalyptic number.

It is an amenable number.

20990846189 is a deficient number, since it is larger than the sum of its proper divisors (1).

20990846189 is an equidigital number, since it uses as much as digits as its factorization.

20990846189 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2239488, while the sum is 56.

The spelling of 20990846189 in words is "twenty billion, nine hundred ninety million, eight hundred forty-six thousand, one hundred eighty-nine".