20794364821 has 4 divisors (see below), whose sum is σ = 20835218700. Its totient is φ = 20753510944.

The previous prime is 20794364819. The next prime is 20794364863. The reversal of 20794364821 is 12846349702.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 10264526596 + 10529838225 = 101314^2 + 102615^2 .

It is a cyclic number.

It is not a de Polignac number, because 20794364821 - 2¹ = 20794364819 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20794364881) 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 3 ways as a sum of consecutive naturals, for example, 20426176 + ... + 20427193.

It is an arithmetic number, because the mean of its divisors is an integer number (5208804675).

Almost surely, 2^20794364821 is an apocalyptic number.

It is an amenable number.

20794364821 is a deficient number, since it is larger than the sum of its proper divisors (40853879).

20794364821 is an equidigital number, since it uses as much as digits as its factorization.

20794364821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40853878.

The product of its (nonzero) digits is 580608, while the sum is 46.

The spelling of 20794364821 in words is "twenty billion, seven hundred ninety-four million, three hundred sixty-four thousand, eight hundred twenty-one".