84421991808 has 384 divisors, whose sum is σ = 309074688000. Its totient is φ = 21926661120.

The previous prime is 84421991807. The next prime is 84421991831. The reversal of 84421991808 is 80819912448.

It is a happy number.

84421991808 is a `hidden beast` number, since 8 + 442 + 19 + 9 + 180 + 8 = 666.

It is a tau number, because it is divible by the number of its divisors (384).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (84421991807) by changing a digit.

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 47 ways as a sum of consecutive naturals, for example, 4336785 + ... + 4356207.

It is an arithmetic number, because the mean of its divisors is an integer number (804882000).

Almost surely, 2^84421991808 is an apocalyptic number.

84421991808 is a gapful number since it is divisible by the number (88) 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 84421991808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (154537344000).

84421991808 is an abundant number, since it is smaller than the sum of its proper divisors (224652696192).

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

84421991808 is a wasteful number, since it uses less digits than its factorization.

84421991808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19475 (or 19446 counting only the distinct ones).

The product of its (nonzero) digits is 1327104, while the sum is 54.

The spelling of 84421991808 in words is "eighty-four billion, four hundred twenty-one million, nine hundred ninety-one thousand, eight hundred eight".