21321352212 has 12 divisors (see below), whose sum is σ = 49749821856. Its totient is φ = 7107117400.

The previous prime is 21321352147. The next prime is 21321352219. The reversal of 21321352212 is 21225312312.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21321352219) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 888389664 + ... + 888389687.

It is an arithmetic number, because the mean of its divisors is an integer number (4145818488).

Almost surely, 2^21321352212 is an apocalyptic number.

It is an amenable number.

21321352212 is an abundant number, since it is smaller than the sum of its proper divisors (28428469644).

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

21321352212 is a wasteful number, since it uses less digits than its factorization.

21321352212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1776779358 (or 1776779356 counting only the distinct ones).

The product of its digits is 1440, while the sum is 24.

Adding to 21321352212 its reverse (21225312312), we get a palindrome (42546664524).

The spelling of 21321352212 in words is "twenty-one billion, three hundred twenty-one million, three hundred fifty-two thousand, two hundred twelve".