20581163 has 2 divisors, whose sum is σ = 20581164. Its totient is φ = 20581162.

The previous prime is 20581153. The next prime is 20581189. The reversal of 20581163 is 36118502.

It is an a-pointer prime, because the next prime (20581189) can be obtained adding 20581163 to its sum of digits (26).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20581163 - 2²² = 16386859 is a prime.

It is not a weakly prime, because it can be changed into another prime (20581103) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10290581 + 10290582.

It is an arithmetic number, because the mean of its divisors is an integer number (10290582).

Almost surely, 2^20581163 is an apocalyptic number.

20581163 is a deficient number, since it is larger than the sum of its proper divisors (1).

20581163 is an equidigital number, since it uses as much as digits as its factorization.

20581163 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1440, while the sum is 26.

The square root of 20581163 is about 4536.6466690718. The cubic root of 20581163 is about 274.0458969060.

Adding to 20581163 its reverse (36118502), we get a palindrome (56699665).

The spelling of 20581163 in words is "twenty million, five hundred eighty-one thousand, one hundred sixty-three".