21012221199968 has 48 divisors (see below), whose sum is σ = 42333379038720. Its totient is φ = 10260927551616.

The previous prime is 21012221199941. The next prime is 21012221199979. The reversal of 21012221199968 is 86999112221012.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16045721 + ... + 17305767.

It is an arithmetic number, because the mean of its divisors is an integer number (881945396640).

Almost surely, 2^{21012221199968} is an apocalyptic number.

It is an amenable number.

21012221199968 is an abundant number, since it is smaller than the sum of its proper divisors (21321157838752).

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

21012221199968 is a wasteful number, since it uses less digits than its factorization.

21012221199968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1272219 (or 1272211 counting only the distinct ones).

The product of its (nonzero) digits is 559872, while the sum is 53.

The spelling of 21012221199968 in words is "twenty-one trillion, twelve billion, two hundred twenty-one million, one hundred ninety-nine thousand, nine hundred sixty-eight".