21012221199969 has 12 divisors (see below), whose sum is σ = 30923646294996. Its totient is φ = 13743842797152.

The previous prime is 21012221199941. The next prime is 21012221199979. The reversal of 21012221199969 is 96999112221012.

21012221199969 is a `hidden beast` number, since 210 + 1 + 222 + 119 + 9 + 96 + 9 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 11434508435025 + 9577712764944 = 3381495^2 + 3094788^2 .

It is not a de Polignac number, because 21012221199969 - 2²⁴ = 21012204422753 is a prime.

It is a super-2 number, since 2×21012221199969² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21012221199979) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 22025388622 + ... + 22025389575.

It is an arithmetic number, because the mean of its divisors is an integer number (2576970524583).

Almost surely, 2^{21012221199969} is an apocalyptic number.

It is an amenable number.

21012221199969 is a deficient number, since it is larger than the sum of its proper divisors (9911425095027).

21012221199969 is a wasteful number, since it uses less digits than its factorization.

21012221199969 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44050778256 (or 44050778253 counting only the distinct ones).

The product of its (nonzero) digits is 629856, while the sum is 54.

The spelling of 21012221199969 in words is "twenty-one trillion, twelve billion, two hundred twenty-one million, one hundred ninety-nine thousand, nine hundred sixty-nine".