21211210212 has 48 divisors (see below), whose sum is σ = 49897774080. Its totient is φ = 7012731168.

The previous prime is 21211210211. The next prime is 21211210219. The reversal of 21211210212 is 21201211212.

It is a junction number, because it is equal to n+sod(n) for n = 21211210191 and 21211210200.

It is not an unprimeable number, because it can be changed into a prime (21211210211) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 973089 + ... + 994647.

It is an arithmetic number, because the mean of its divisors is an integer number (1039536960).

Almost surely, 2^21211210212 is an apocalyptic number.

It is an amenable number.

21211210212 is an abundant number, since it is smaller than the sum of its proper divisors (28686563868).

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

21211210212 is a wasteful number, since it uses less digits than its factorization.

21211210212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22232 (or 22230 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 21211210212 its reverse (21201211212), we get a palindrome (42412421424).

The spelling of 21211210212 in words is "twenty-one billion, two hundred eleven million, two hundred ten thousand, two hundred twelve".