21320313212 has 24 divisors (see below), whose sum is σ = 42844650240. Its totient is φ = 9180995760.

The previous prime is 21320313211. The next prime is 21320313229. The reversal of 21320313212 is 21231302312.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21320313211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12750548 + ... + 12752219.

It is an arithmetic number, because the mean of its divisors is an integer number (1785193760).

Almost surely, 2^21320313212 is an apocalyptic number.

21320313212 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21320313212 is an abundant number, since it is smaller than the sum of its proper divisors (21524337028).

21320313212 is a wasteful number, since it uses less digits than its factorization.

21320313212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25502801 (or 25502799 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 20.

Adding to 21320313212 its reverse (21231302312), we get a palindrome (42551615524).

The spelling of 21320313212 in words is "twenty-one billion, three hundred twenty million, three hundred thirteen thousand, two hundred twelve".