21006684280512 has 336 divisors, whose sum is σ = 69172503109632. Its totient is φ = 5970651033600.

The previous prime is 21006684280471. The next prime is 21006684280537. The reversal of 21006684280512 is 21508248660012.

21006684280512 is a `hidden beast` number, since 2 + 10 + 0 + 6 + 6 + 8 + 42 + 80 + 512 = 666.

It is a tau number, because it is divible by the number of its divisors (336).

It is a super-2 number, since 2×21006684280512² (a number of 27 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1081304143 + ... + 1081323569.

Almost surely, 2^{21006684280512} 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 21006684280512, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34586251554816).

21006684280512 is an abundant number, since it is smaller than the sum of its proper divisors (48165818829120).

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

21006684280512 is a wasteful number, since it uses less digits than its factorization.

21006684280512 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20836 (or 20823 counting only the distinct ones).

The product of its (nonzero) digits is 368640, while the sum is 45.

The spelling of 21006684280512 in words is "twenty-one trillion, six billion, six hundred eighty-four million, two hundred eighty thousand, five hundred twelve".