21212010312 has 64 divisors (see below), whose sum is σ = 54502761600. Its totient is φ = 6874583040.

The previous prime is 21212010311. The next prime is 21212010317. The reversal of 21212010312 is 21301021212.

It is a junction number, because it is equal to n+sod(n) for n = 21212010291 and 21212010300.

It is not an unprimeable number, because it can be changed into a prime (21212010311) 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, 1333864 + ... + 1349672.

It is an arithmetic number, because the mean of its divisors is an integer number (851605650).

Almost surely, 2^21212010312 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21212010312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27251380800).

21212010312 is an abundant number, since it is smaller than the sum of its proper divisors (33290751288).

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

21212010312 is a wasteful number, since it uses less digits than its factorization.

21212010312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17366 (or 17362 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 15.

Adding to 21212010312 its reverse (21301021212), we get a palindrome (42513031524).

The spelling of 21212010312 in words is "twenty-one billion, two hundred twelve million, ten thousand, three hundred twelve".