21605028210668 has 24 divisors (see below), whose sum is σ = 43210299912192. Its totient is φ = 9259245627984.

The previous prime is 21605028210659. The next prime is 21605028210721. The reversal of 21605028210668 is 86601282050612.

21605028210668 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 3108821 + ... + 7271507.

It is an arithmetic number, because the mean of its divisors is an integer number (1800429163008).

Almost surely, 2^{21605028210668} is an apocalyptic number.

21605028210668 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21605028210668 is an abundant number, since it is smaller than the sum of its proper divisors (21605271701524).

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

21605028210668 is a wasteful number, since it uses less digits than its factorization.

21605028210668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4348061 (or 4348059 counting only the distinct ones).

The product of its (nonzero) digits is 552960, while the sum is 47.

The spelling of 21605028210668 in words is "twenty-one trillion, six hundred five billion, twenty-eight million, two hundred ten thousand, six hundred sixty-eight".