321212221220 has 192 divisors, whose sum is σ = 795808419840. Its totient is φ = 107642649600.

The previous prime is 321212221217. The next prime is 321212221223. The reversal of 321212221220 is 22122212123.

It is an interprime number because it is at equal distance from previous prime (321212221217) and next prime (321212221223).

It is a super-2 number, since 2×321212221220² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 321212221192 and 321212221201.

It is not an unprimeable number, because it can be changed into a prime (321212221223) 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 63 ways as a sum of consecutive naturals, for example, 62893907 + ... + 62899013.

It is an arithmetic number, because the mean of its divisors is an integer number (4144835520).

Almost surely, 2^321212221220 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 321212221220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (397904209920).

321212221220 is an abundant number, since it is smaller than the sum of its proper divisors (474596198620).

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

321212221220 is a wasteful number, since it uses less digits than its factorization.

321212221220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5554 (or 5552 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 20.

Adding to 321212221220 its reverse (22122212123), we get a palindrome (343334433343).

The spelling of 321212221220 in words is "three hundred twenty-one billion, two hundred twelve million, two hundred twenty-one thousand, two hundred twenty".