221221110101100 has 144 divisors (see below), whose sum is σ = 643325996750976. Its totient is φ = 58692070080000.

The previous prime is 221221110101099. The next prime is 221221110101149. The reversal of 221221110101100 is 1101011122122.

It is a happy number.

221221110101100 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 221221110101100.

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, 179855392 + ... + 181081208.

It is an arithmetic number, because the mean of its divisors is an integer number (4467541644104).

Almost surely, 2^{221221110101100} is an apocalyptic number.

221221110101100 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 221221110101100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (321662998375488).

221221110101100 is an abundant number, since it is smaller than the sum of its proper divisors (422104886649876).

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

221221110101100 is a wasteful number, since it uses less digits than its factorization.

221221110101100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1228896 (or 1228889 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 221221110101100 its reverse (1101011122122), we get a palindrome (222322121223222).

The spelling of 221221110101100 in words is "two hundred twenty-one trillion, two hundred twenty-one billion, one hundred ten million, one hundred one thousand, one hundred".