820389983400 has 360 divisors, whose sum is σ = 3085385912730. Its totient is φ = 201941475840.

The previous prime is 820389983393. The next prime is 820389983419. The reversal of 820389983400 is 4389983028.

It is a happy number.

820389983400 is a `hidden beast` number, since 8 + 203 + 8 + 9 + 98 + 340 + 0 = 666.

It can be written as a sum of positive squares in 9 ways, for example, as 4775086404 + 815614896996 = 69102^2 + 903114^2 .

It is a tau number, because it is divible by the number of its divisors (360).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 89 ways as a sum of consecutive naturals, for example, 2587974 + ... + 2887626.

Almost surely, 2^820389983400 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 820389983400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1542692956365).

820389983400 is an abundant number, since it is smaller than the sum of its proper divisors (2264995929330).

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

820389983400 is a wasteful number, since it uses less digits than its factorization.

820389983400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 299707 (or 299676 counting only the distinct ones).

The product of its (nonzero) digits is 2985984, while the sum is 54.

The spelling of 820389983400 in words is "eight hundred twenty billion, three hundred eighty-nine million, nine hundred eighty-three thousand, four hundred".