820216320 has 640 divisors, whose sum is σ = 3488348160. Its totient is φ = 159252480.

The previous prime is 820216307. The next prime is 820216337. The reversal of 820216320 is 23612028.

It is a tau number, because it is divible by the number of its divisors (640).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 11235804 + ... + 11235876.

It is an arithmetic number, because the mean of its divisors is an integer number (5450544).

Almost surely, 2^820216320 is an apocalyptic number.

820216320 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 820216320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1744174080).

820216320 is an abundant number, since it is smaller than the sum of its proper divisors (2668131840).

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

820216320 is a wasteful number, since it uses less digits than its factorization.

820216320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136 (or 120 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 24.

The square root of 820216320 is about 28639.4189885200. The cubic root of 820216320 is about 936.0724613345.

Adding to 820216320 its reverse (23612028), we get a palindrome (843828348).

The spelling of 820216320 in words is "eight hundred twenty million, two hundred sixteen thousand, three hundred twenty".