21212320221012 has 24 divisors (see below), whose sum is σ = 49495499776800. Its totient is φ = 7070761131616.

The previous prime is 21212320220921. The next prime is 21212320221013. The reversal of 21212320221012 is 21012202321212.

It is a self number, because there is not a number n which added to its sum of digits gives 21212320221012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21212320221013) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8070814 + ... + 10371242.

It is an arithmetic number, because the mean of its divisors is an integer number (2062312490700).

Almost surely, 2^{21212320221012} is an apocalyptic number.

It is an amenable number.

21212320221012 is an abundant number, since it is smaller than the sum of its proper divisors (28283179555788).

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

21212320221012 is a wasteful number, since it uses less digits than its factorization.

21212320221012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3068855 (or 3068853 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 21.

Adding to 21212320221012 its reverse (21012202321212), we get a palindrome (42224522542224).

The spelling of 21212320221012 in words is "twenty-one trillion, two hundred twelve billion, three hundred twenty million, two hundred twenty-one thousand, twelve".