21212030312 has 64 divisors (see below), whose sum is σ = 45719078400. Its totient is φ = 9124920000.

The previous prime is 21212030303. The next prime is 21212030363. The reversal of 21212030312 is 21303021212.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1751237 + ... + 1763307.

It is an arithmetic number, because the mean of its divisors is an integer number (714360600).

Almost surely, 2^21212030312 is an apocalyptic number.

21212030312 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21212030312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22859539200).

21212030312 is an abundant number, since it is smaller than the sum of its proper divisors (24507048088).

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

21212030312 is a wasteful number, since it uses less digits than its factorization.

21212030312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13158 (or 13154 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 17.

Adding to 21212030312 its reverse (21303021212), we get a palindrome (42515051524).

The spelling of 21212030312 in words is "twenty-one billion, two hundred twelve million, thirty thousand, three hundred twelve".