221021220012 has 72 divisors (see below), whose sum is σ = 548930382336. Its totient is φ = 69201591552.

The previous prime is 221021219999. The next prime is 221021220023. The reversal of 221021220012 is 210022120122.

It is a junction number, because it is equal to n+sod(n) for n = 221021219973 and 221021220000.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1681053 + ... + 1807755.

It is an arithmetic number, because the mean of its divisors is an integer number (7624033088).

Almost surely, 2^221021220012 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 221021220012, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (274465191168).

221021220012 is an abundant number, since it is smaller than the sum of its proper divisors (327909162324).

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

221021220012 is a wasteful number, since it uses less digits than its factorization.

221021220012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 127247 (or 127228 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 221021220012 its reverse (210022120122), we get a palindrome (431043340134).

The spelling of 221021220012 in words is "two hundred twenty-one billion, twenty-one million, two hundred twenty thousand, twelve".