20863866563 has 16 divisors (see below), whose sum is σ = 21491244000. Its totient is φ = 20246383872.

The previous prime is 20863866553. The next prime is 20863866571. The reversal of 20863866563 is 36566836802.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 20863866563 - 2¹⁶ = 20863801027 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20863866553) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3551993 + ... + 3557861.

It is an arithmetic number, because the mean of its divisors is an integer number (1343202750).

Almost surely, 2^20863866563 is an apocalyptic number.

20863866563 is a deficient number, since it is larger than the sum of its proper divisors (627377437).

20863866563 is an equidigital number, since it uses as much as digits as its factorization.

20863866563 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6694.

The product of its (nonzero) digits is 7464960, while the sum is 53.

The spelling of 20863866563 in words is "twenty billion, eight hundred sixty-three million, eight hundred sixty-six thousand, five hundred sixty-three".