20847820189 has 4 divisors (see below), whose sum is σ = 23826080224. Its totient is φ = 17869560156.

The previous prime is 20847820153. The next prime is 20847820193. The reversal of 20847820189 is 98102874802.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 20847820189 - 2⁷ = 20847820061 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 (20847820789) 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, 1489130007 + ... + 1489130020.

It is an arithmetic number, because the mean of its divisors is an integer number (5956520056).

Almost surely, 2^20847820189 is an apocalyptic number.

It is an amenable number.

20847820189 is a deficient number, since it is larger than the sum of its proper divisors (2978260035).

20847820189 is an equidigital number, since it uses as much as digits as its factorization.

20847820189 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2978260034.

The product of its (nonzero) digits is 516096, while the sum is 49.

The spelling of 20847820189 in words is "twenty billion, eight hundred forty-seven million, eight hundred twenty thousand, one hundred eighty-nine".