7821100800 has 648 divisors, whose sum is σ = 29891586816. Its totient is φ = 2022174720.

The previous prime is 7821100783. The next prime is 7821100831. The reversal of 7821100800 is 80011287.

It is a tau number, because it is divible by the number of its divisors (648).

It is a super-2 number, since 2×7821100800² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 73094347 + ... + 73094453.

It is an arithmetic number, because the mean of its divisors is an integer number (46128992).

Almost surely, 2^7821100800 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 7821100800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (14945793408).

7821100800 is an abundant number, since it is smaller than the sum of its proper divisors (22070486016).

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

7821100800 is a wasteful number, since it uses less digits than its factorization.

7821100800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 195 (or 164 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 27.

The square root of 7821100800 is about 88436.9877370323. The cubic root of 7821100800 is about 1984.9792035924.

The spelling of 7821100800 in words is "seven billion, eight hundred twenty-one million, one hundred thousand, eight hundred".