21201020212 has 12 divisors (see below), whose sum is σ = 39284243460. Its totient is φ = 9976950656.

The previous prime is 21201020189. The next prime is 21201020251. The reversal of 21201020212 is 21202010212.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 14593606416 + 6607413796 = 120804^2 + 81286^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21201020192 and 21201020201.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 155889787 + ... + 155889922.

It is an arithmetic number, because the mean of its divisors is an integer number (3273686955).

Almost surely, 2^21201020212 is an apocalyptic number.

It is an amenable number.

21201020212 is a deficient number, since it is larger than the sum of its proper divisors (18083223248).

21201020212 is a wasteful number, since it uses less digits than its factorization.

21201020212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 311779730 (or 311779728 counting only the distinct ones).

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

Adding to 21201020212 its reverse (21202010212), we get a palindrome (42403030424).

The spelling of 21201020212 in words is "twenty-one billion, two hundred one million, twenty thousand, two hundred twelve".