21000020021212 has 24 divisors (see below), whose sum is σ = 37102505416704. Its totient is φ = 10399585884912.

The previous prime is 21000020021153. The next prime is 21000020021213. The reversal of 21000020021212 is 21212002000012.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21000020021192 and 21000020021201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21000020021213) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 34913578 + ... + 35509969.

It is an arithmetic number, because the mean of its divisors is an integer number (1545937725696).

Almost surely, 2^{21000020021212} is an apocalyptic number.

It is an amenable number.

21000020021212 is a deficient number, since it is larger than the sum of its proper divisors (16102485395492).

21000020021212 is a wasteful number, since it uses less digits than its factorization.

21000020021212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70424265 (or 70424263 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 21000020021212 its reverse (21212002000012), we get a palindrome (42212022021224).

The spelling of 21000020021212 in words is "twenty-one trillion, twenty million, twenty-one thousand, two hundred twelve".