21816379802016 has 144 divisors (see below), whose sum is σ = 63358582439880. Its totient is φ = 7119224217600.

The previous prime is 21816379801969. The next prime is 21816379802027. The reversal of 21816379802016 is 61020897361812.

21816379802016 is a `hidden beast` number, since 2 + 181 + 6 + 379 + 80 + 2 + 0 + 16 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 18712511033616 + 3103868768400 = 4325796^2 + 1761780^2 .

It is a tau number, because it is divible by the number of its divisors (144).

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 23 ways as a sum of consecutive naturals, for example, 1624725 + ... + 6802388.

Almost surely, 2^{21816379802016} is an apocalyptic number.

It is an amenable number.

21816379802016 is an abundant number, since it is smaller than the sum of its proper divisors (41542202637864).

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

21816379802016 is a wasteful number, since it uses less digits than its factorization.

21816379802016 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8427319 (or 8427308 counting only the distinct ones).

The product of its (nonzero) digits is 1741824, while the sum is 54.

The spelling of 21816379802016 in words is "twenty-one trillion, eight hundred sixteen billion, three hundred seventy-nine million, eight hundred two thousand, sixteen".