820649921600 has 336 divisors, whose sum is σ = 2178132840576. Its totient is φ = 303206400000.

The previous prime is 820649921591. The next prime is 820649921653. The reversal of 820649921600 is 6129946028.

It is a super-2 number, since 2×820649921600² (a number of 25 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 484730354 + ... + 484732046.

It is an arithmetic number, because the mean of its divisors is an integer number (6482538216).

Almost surely, 2^820649921600 is an apocalyptic number.

820649921600 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 820649921600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1089066420288).

820649921600 is an abundant number, since it is smaller than the sum of its proper divisors (1357482918976).

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

820649921600 is a wasteful number, since it uses less digits than its factorization.

820649921600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2054 (or 2039 counting only the distinct ones).

The product of its (nonzero) digits is 373248, while the sum is 47.

The spelling of 820649921600 in words is "eight hundred twenty billion, six hundred forty-nine million, nine hundred twenty-one thousand, six hundred".