221001221021100 has 288 divisors, whose sum is σ = 689603562547200. Its totient is φ = 54322427381760.

The previous prime is 221001221021093. The next prime is 221001221021131. The reversal of 221001221021100 is 1120122100122.

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 221001221021100.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 8911686501 + ... + 8911711299.

It is an arithmetic number, because the mean of its divisors is an integer number (2394456814400).

Almost surely, 2^{221001221021100} is an apocalyptic number.

221001221021100 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 221001221021100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (344801781273600).

221001221021100 is an abundant number, since it is smaller than the sum of its proper divisors (468602341526100).

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

221001221021100 is a wasteful number, since it uses less digits than its factorization.

221001221021100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28009 (or 28002 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 221001221021100 its reverse (1120122100122), we get a palindrome (222121343121222).

The spelling of 221001221021100 in words is "two hundred twenty-one trillion, one billion, two hundred twenty-one million, twenty-one thousand, one hundred".