20487563 has 2 divisors, whose sum is σ = 20487564. Its totient is φ = 20487562.

The previous prime is 20487527. The next prime is 20487569. The reversal of 20487563 is 36578402.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20487563 - 2¹⁰ = 20486539 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (20487569) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10243781 + 10243782.

It is an arithmetic number, because the mean of its divisors is an integer number (10243782).

Almost surely, 2^20487563 is an apocalyptic number.

20487563 is a deficient number, since it is larger than the sum of its proper divisors (1).

20487563 is an equidigital number, since it uses as much as digits as its factorization.

20487563 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 40320, while the sum is 35.

The square root of 20487563 is about 4526.3189238055. The cubic root of 20487563 is about 273.6298258341.

The spelling of 20487563 in words is "twenty million, four hundred eighty-seven thousand, five hundred sixty-three".