221022221100 has 144 divisors (see below), whose sum is σ = 672388943520. Its totient is φ = 55973836800.

The previous prime is 221022221099. The next prime is 221022221131. The reversal of 221022221100 is 1122220122.

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 221022221100.

It is an unprimeable number.

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 47 ways as a sum of consecutive naturals, for example, 322464 + ... + 738936.

Almost surely, 2^221022221100 is an apocalyptic number.

221022221100 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 221022221100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (336194471760).

221022221100 is an abundant number, since it is smaller than the sum of its proper divisors (451366722420).

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

221022221100 is a wasteful number, since it uses less digits than its factorization.

221022221100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 416580 (or 416573 counting only the distinct ones).

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

Adding to 221022221100 its reverse (1122220122), we get a palindrome (222144441222).

It can be divided in two parts, 2210222 and 21100, that added together give a palindrome (2231322).

The spelling of 221022221100 in words is "two hundred twenty-one billion, twenty-two million, two hundred twenty-one thousand, one hundred".