21208428184320 has 1008 divisors, whose sum is σ = 83418403733280. Its totient is φ = 5131879317504.

The previous prime is 21208428184219. The next prime is 21208428184337. The reversal of 21208428184320 is 2348182480212.

21208428184320 is a `hidden beast` number, since 2 + 1 + 20 + 8 + 428 + 184 + 3 + 20 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 111 ways as a sum of consecutive naturals, for example, 715688224 + ... + 715717856.

It is an arithmetic number, because the mean of its divisors is an integer number (82756352910).

Almost surely, 2^{21208428184320} is an apocalyptic number.

21208428184320 is a gapful number since it is divisible by the number (20) 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 21208428184320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41709201866640).

21208428184320 is an abundant number, since it is smaller than the sum of its proper divisors (62209975548960).

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

21208428184320 is an equidigital number, since it uses as much as digits as its factorization.

21208428184320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29744 (or 29715 counting only the distinct ones).

The product of its (nonzero) digits is 393216, while the sum is 45.

The spelling of 21208428184320 in words is "twenty-one trillion, two hundred eight billion, four hundred twenty-eight million, one hundred eighty-four thousand, three hundred twenty".