221100012 has 144 divisors (see below), whose sum is σ = 685181952. Its totient is φ = 58734720.

The previous prime is 221099999. The next prime is 221100037. The reversal of 221100012 is 210001122.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 221099967 and 221100003.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 213937 + ... + 214967.

It is an arithmetic number, because the mean of its divisors is an integer number (4758208).

Almost surely, 2^221100012 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 221100012, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (342590976).

221100012 is an abundant number, since it is smaller than the sum of its proper divisors (464081940).

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

221100012 is a wasteful number, since it uses less digits than its factorization.

221100012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1108 (or 1103 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

The square root of 221100012 is about 14869.4321344159. The cubic root of 221100012 is about 604.6855474928.

Adding to 221100012 its reverse (210001122), we get a palindrome (431101134).

The spelling of 221100012 in words is "two hundred twenty-one million, one hundred thousand, twelve".