21284475387808 has 96 divisors (see below), whose sum is σ = 42996672875520. Its totient is φ = 10366852515840.

The previous prime is 21284475387787. The next prime is 21284475387811. The reversal of 21284475387808 is 80878357448212.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 960523033 + ... + 960545191.

It is an arithmetic number, because the mean of its divisors is an integer number (447882009120).

Almost surely, 2^{21284475387808} 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 21284475387808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21498336437760).

21284475387808 is an abundant number, since it is smaller than the sum of its proper divisors (21712197487712).

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

21284475387808 is a wasteful number, since it uses less digits than its factorization.

21284475387808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25190 (or 25182 counting only the distinct ones).

The product of its (nonzero) digits is 192675840, while the sum is 67.

The spelling of 21284475387808 in words is "twenty-one trillion, two hundred eighty-four billion, four hundred seventy-five million, three hundred eighty-seven thousand, eight hundred eight".