221202212100 has 144 divisors (see below), whose sum is σ = 646181891712. Its totient is φ = 58419415040.

The previous prime is 221202212083. The next prime is 221202212141. The reversal of 221202212100 is 1212202122.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 221202212100.

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, 82138354 + ... + 82141046.

It is an arithmetic number, because the mean of its divisors is an integer number (4487374248).

Almost surely, 2^221202212100 is an apocalyptic number.

221202212100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221202212100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (323090945856).

221202212100 is an abundant number, since it is smaller than the sum of its proper divisors (424979679612).

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

221202212100 is a wasteful number, since it uses less digits than its factorization.

221202212100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5246 (or 5239 counting only the distinct ones).

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

Adding to 221202212100 its reverse (1212202122), we get a palindrome (222414414222).

The spelling of 221202212100 in words is "two hundred twenty-one billion, two hundred two million, two hundred twelve thousand, one hundred".