20636403563 has 2 divisors, whose sum is σ = 20636403564. Its totient is φ = 20636403562.

The previous prime is 20636403559. The next prime is 20636403607. The reversal of 20636403563 is 36530463602.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20636403563 - 2² = 20636403559 is a prime.

It is a super-2 number, since 2×20636403563² (a number of 21 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (20636403533) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10318201781 + 10318201782.

It is an arithmetic number, because the mean of its divisors is an integer number (10318201782).

Almost surely, 2^20636403563 is an apocalyptic number.

20636403563 is a deficient number, since it is larger than the sum of its proper divisors (1).

20636403563 is an equidigital number, since it uses as much as digits as its factorization.

20636403563 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 233280, while the sum is 38.

The spelling of 20636403563 in words is "twenty billion, six hundred thirty-six million, four hundred three thousand, five hundred sixty-three".