820209823524 has 336 divisors, whose sum is σ = 2734166256640. Its totient is φ = 209338940160.

The previous prime is 820209823519. The next prime is 820209823567. The reversal of 820209823524 is 425328902028.

820209823524 is a `hidden beast` number, since 8 + 20 + 20 + 9 + 82 + 3 + 524 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 820209823524.

It is an unprimeable number.

It is a polite number, since it can be written in 111 ways as a sum of consecutive naturals, for example, 8176182 + ... + 8275890.

Almost surely, 2^820209823524 is an apocalyptic number.

820209823524 is a gapful number since it is divisible by the number (84) 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 820209823524, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1367083128320).

820209823524 is an abundant number, since it is smaller than the sum of its proper divisors (1913956433116).

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

820209823524 is a wasteful number, since it uses less digits than its factorization.

820209823524 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 99782 (or 99765 counting only the distinct ones).

The product of its (nonzero) digits is 552960, while the sum is 45.

The spelling of 820209823524 in words is "eight hundred twenty billion, two hundred nine million, eight hundred twenty-three thousand, five hundred twenty-four".