20820079789 has 4 divisors (see below), whose sum is σ = 20820560956. Its totient is φ = 20819598624.

The previous prime is 20820079747. The next prime is 20820079793. The reversal of 20820079789 is 98797002802.

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 19034341225 + 1785738564 = 137965^2 + 42258^2 .

It is a cyclic number.

It is not a de Polignac number, because 20820079789 - 2¹⁷ = 20819948717 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 (20820079289) 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, 168474 + ... + 264619.

It is an arithmetic number, because the mean of its divisors is an integer number (5205140239).

Almost surely, 2^20820079789 is an apocalyptic number.

It is an amenable number.

20820079789 is a deficient number, since it is larger than the sum of its proper divisors (481167).

20820079789 is an equidigital number, since it uses as much as digits as its factorization.

20820079789 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 481166.

The product of its (nonzero) digits is 1016064, while the sum is 52.

The spelling of 20820079789 in words is "twenty billion, eight hundred twenty million, seventy-nine thousand, seven hundred eighty-nine".