221220221100 has 72 divisors (see below), whose sum is σ = 640128404160. Its totient is φ = 58986108480.

The previous prime is 221220221093. The next prime is 221220221143. The reversal of 221220221100 is 1122022122.

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 221220221100.

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, 3502399 + ... + 3565001.

It is an arithmetic number, because the mean of its divisors is an integer number (8890672280).

Almost surely, 2^221220221100 is an apocalyptic number.

221220221100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221220221100 is an abundant number, since it is smaller than the sum of its proper divisors (418908183060).

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

221220221100 is a wasteful number, since it uses less digits than its factorization.

221220221100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74399 (or 74392 counting only the distinct ones).

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

Adding to 221220221100 its reverse (1122022122), we get a palindrome (222342243222).

The spelling of 221220221100 in words is "two hundred twenty-one billion, two hundred twenty million, two hundred twenty-one thousand, one hundred".