820109880 has 128 divisors (see below), whose sum is σ = 2800526400. Its totient is φ = 213350400.

The previous prime is 820109837. The next prime is 820109881. The reversal of 820109880 is 88901028.

It is a super-2 number, since 2×820109880² = 1345160430547228800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (820109881) 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 31 ways as a sum of consecutive naturals, for example, 35020 + ... + 53540.

Almost surely, 2^820109880 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 820109880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1400263200).

820109880 is an abundant number, since it is smaller than the sum of its proper divisors (1980416520).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

820109880 is a wasteful number, since it uses less digits than its factorization.

820109880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18582 (or 18572 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 36.

The square root of 820109880 is about 28637.5606503068. The cubic root of 820109880 is about 936.0319680074.

The spelling of 820109880 in words is "eight hundred twenty million, one hundred nine thousand, eight hundred eighty".