20819831139 has 8 divisors (see below), whose sum is σ = 30844194320. Its totient is φ = 13879887408.

The previous prime is 20819831113. The next prime is 20819831141. The reversal of 20819831139 is 93113891802.

It is not a de Polignac number, because 20819831139 - 2¹¹ = 20819829091 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20819831094 and 20819831103.

It is not an unprimeable number, because it can be changed into a prime (20819831839) 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 7 ways as a sum of consecutive naturals, for example, 385552402 + ... + 385552455.

It is an arithmetic number, because the mean of its divisors is an integer number (3855524290).

Almost surely, 2^20819831139 is an apocalyptic number.

20819831139 is a deficient number, since it is larger than the sum of its proper divisors (10024363181).

20819831139 is an equidigital number, since it uses as much as digits as its factorization.

20819831139 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 771104866 (or 771104860 counting only the distinct ones).

The product of its (nonzero) digits is 93312, while the sum is 45.

The spelling of 20819831139 in words is "twenty billion, eight hundred nineteen million, eight hundred thirty-one thousand, one hundred thirty-nine".