20581189 has 2 divisors, whose sum is σ = 20581190. Its totient is φ = 20581188.

The previous prime is 20581163. The next prime is 20581201. The reversal of 20581189 is 98118502.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13264164 + 7317025 = 3642^2 + 2705^2 .

It is a cyclic number.

It is not a de Polignac number, because 20581189 - 2¹⁷ = 20450117 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20588189) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10290594 + 10290595.

It is an arithmetic number, because the mean of its divisors is an integer number (10290595).

Almost surely, 2^20581189 is an apocalyptic number.

It is an amenable number.

20581189 is a deficient number, since it is larger than the sum of its proper divisors (1).

20581189 is an equidigital number, since it uses as much as digits as its factorization.

20581189 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5760, while the sum is 34.

The square root of 20581189 is about 4536.6495346235. The cubic root of 20581189 is about 274.0460123058.

The spelling of 20581189 in words is "twenty million, five hundred eighty-one thousand, one hundred eighty-nine".