20013563 has 2 divisors, whose sum is σ = 20013564. Its totient is φ = 20013562.

The previous prime is 20013557. The next prime is 20013577. The reversal of 20013563 is 36531002.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20013563 - 2⁴ = 20013547 is a prime.

It is not a weakly prime, because it can be changed into another prime (20013523) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10006781 + 10006782.

It is an arithmetic number, because the mean of its divisors is an integer number (10006782).

Almost surely, 2^20013563 is an apocalyptic number.

20013563 is a deficient number, since it is larger than the sum of its proper divisors (1).

20013563 is an equidigital number, since it uses as much as digits as its factorization.

20013563 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 540, while the sum is 20.

The square root of 20013563 is about 4473.6520875008. The cubic root of 20013563 is about 271.5031072046.

Adding to 20013563 its reverse (36531002), we get a palindrome (56544565).

The spelling of 20013563 in words is "twenty million, thirteen thousand, five hundred sixty-three".