820004189 has 4 divisors (see below), whose sum is σ = 820533756. Its totient is φ = 819474624.

The previous prime is 820004137. The next prime is 820004233. The reversal of 820004189 is 981400028.

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 409252900 + 410751289 = 20230^2 + 20267^2 .

It is a cyclic number.

It is not a de Polignac number, because 820004189 - 2¹⁶ = 819938653 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 (820004389) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 262454 + ... + 265559.

It is an arithmetic number, because the mean of its divisors is an integer number (205133439).

Almost surely, 2^820004189 is an apocalyptic number.

It is an amenable number.

820004189 is a deficient number, since it is larger than the sum of its proper divisors (529567).

820004189 is a wasteful number, since it uses less digits than its factorization.

820004189 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 529566.

The product of its (nonzero) digits is 4608, while the sum is 32.

The square root of 820004189 is about 28635.7152695720. The cubic root of 820004189 is about 935.9917561581.

The spelling of 820004189 in words is "eight hundred twenty million, four thousand, one hundred eighty-nine".