20816800563 has 32 divisors (see below), whose sum is σ = 31332026880. Its totient is φ = 12207202560.

The previous prime is 20816800553. The next prime is 20816800567. The reversal of 20816800563 is 36500861802.

It is a happy number.

It is not a de Polignac number, because 20816800563 - 2¹⁸ = 20816538419 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is not an unprimeable number, because it can be changed into a prime (20816800567) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 82623 + ... + 220136.

It is an arithmetic number, because the mean of its divisors is an integer number (979125840).

Almost surely, 2^20816800563 is an apocalyptic number.

20816800563 is a deficient number, since it is larger than the sum of its proper divisors (10515226317).

20816800563 is a wasteful number, since it uses less digits than its factorization.

20816800563 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 302859.

The product of its (nonzero) digits is 69120, while the sum is 39.

The spelling of 20816800563 in words is "twenty billion, eight hundred sixteen million, eight hundred thousand, five hundred sixty-three".