20821873558063 has 16 divisors (see below), whose sum is σ = 21252671025696. Its totient is φ = 20395147368960.

The previous prime is 20821873558061. The next prime is 20821873558069. The reversal of 20821873558063 is 36085537812802.

It is a cyclic number.

It is not a de Polignac number, because 20821873558063 - 2¹ = 20821873558061 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20821873557989 and 20821873558007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20821873558061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 21450048 + ... + 22399738.

It is an arithmetic number, because the mean of its divisors is an integer number (1328291939106).

Almost surely, 2^{20821873558063} is an apocalyptic number.

20821873558063 is a deficient number, since it is larger than the sum of its proper divisors (430797467633).

20821873558063 is a wasteful number, since it uses less digits than its factorization.

20821873558063 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 951834.

The product of its (nonzero) digits is 19353600, while the sum is 58.

The spelling of 20821873558063 in words is "twenty trillion, eight hundred twenty-one billion, eight hundred seventy-three million, five hundred fifty-eight thousand, sixty-three".