820221113 has 4 divisors (see below), whose sum is σ = 840226548. Its totient is φ = 800215680.

The previous prime is 820221097. The next prime is 820221121. The reversal of 820221113 is 311122028.

820221113 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 311628409 + 508592704 = 17653^2 + 22552^2 .

It is a cyclic number.

It is not a de Polignac number, because 820221113 - 2⁴ = 820221097 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (820221313) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10002656 + ... + 10002737.

It is an arithmetic number, because the mean of its divisors is an integer number (210056637).

Almost surely, 2^820221113 is an apocalyptic number.

It is an amenable number.

820221113 is a deficient number, since it is larger than the sum of its proper divisors (20005435).

820221113 is a wasteful number, since it uses less digits than its factorization.

820221113 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20005434.

The product of its (nonzero) digits is 192, while the sum is 20.

The square root of 820221113 is about 28639.5026667713. The cubic root of 820221113 is about 936.0742846691.

The spelling of 820221113 in words is "eight hundred twenty million, two hundred twenty-one thousand, one hundred thirteen".