21000212221012 has 24 divisors (see below), whose sum is σ = 38917405220904. Its totient is φ = 9881120166912.

The previous prime is 21000212220991. The next prime is 21000212221039. The reversal of 21000212221012 is 21012221200012.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 2355813637956 + 18644398583056 = 1534866^2 + 4317916^2 .

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, 20314483 + ... + 21323194.

It is an arithmetic number, because the mean of its divisors is an integer number (1621558550871).

Almost surely, 2^{21000212221012} is an apocalyptic number.

It is an amenable number.

21000212221012 is a deficient number, since it is larger than the sum of its proper divisors (17917192999892).

21000212221012 is a wasteful number, since it uses less digits than its factorization.

21000212221012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41645115 (or 41645113 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21000212221012 its reverse (21012221200012), we get a palindrome (42012433421024).

The spelling of 21000212221012 in words is "twenty-one trillion, two hundred twelve million, two hundred twenty-one thousand, twelve".