78499821600 has 720 divisors, whose sum is σ = 304418406600. Its totient is φ = 19647774720.

The previous prime is 78499821557. The next prime is 78499821601. The reversal of 78499821600 is 612899487.

78499821600 is a `hidden beast` number, since 7 + 8 + 4 + 9 + 9 + 8 + 21 + 600 = 666.

It can be written as a sum of positive squares in 12 ways, for example, as 4644149904 + 73855671696 = 68148^2 + 271764^2 .

It is a tau number, because it is divible by the number of its divisors (720).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78499821601) by changing a digit.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 69529836 + ... + 69530964.

Almost surely, 2^78499821600 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 78499821600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (152209203300).

78499821600 is an abundant number, since it is smaller than the sum of its proper divisors (225918585000).

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

78499821600 is a wasteful number, since it uses less digits than its factorization.

78499821600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1227 (or 1205 counting only the distinct ones).

The product of its (nonzero) digits is 1741824, while the sum is 54.

The spelling of 78499821600 in words is "seventy-eight billion, four hundred ninety-nine million, eight hundred twenty-one thousand, six hundred".