820631109 has 16 divisors (see below), whose sum is σ = 1170649280. Its totient is φ = 509794560.

The previous prime is 820631087. The next prime is 820631111. The reversal of 820631109 is 901136028.

820631109 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 820631109 - 2⁷ = 820630981 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (820631129) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 114532 + ... + 121485.

It is an arithmetic number, because the mean of its divisors is an integer number (73165580).

Almost surely, 2^820631109 is an apocalyptic number.

It is an amenable number.

820631109 is a deficient number, since it is larger than the sum of its proper divisors (350018171).

820631109 is a wasteful number, since it uses less digits than its factorization.

820631109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 236100.

The product of its (nonzero) digits is 2592, while the sum is 30.

The square root of 820631109 is about 28646.6596482033. The cubic root of 820631109 is about 936.2302274905.

The spelling of 820631109 in words is "eight hundred twenty million, six hundred thirty-one thousand, one hundred nine".