221021100020100 has 72 divisors (see below), whose sum is σ = 639494990326080. Its totient is φ = 58938289566080.

The previous prime is 221021100020087. The next prime is 221021100020143. The reversal of 221021100020100 is 1020001120122.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 22510081 + ... + 30801719.

It is an arithmetic number, because the mean of its divisors is an integer number (8881874865640).

Almost surely, 2^{221021100020100} is an apocalyptic number.

221021100020100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221021100020100 is an abundant number, since it is smaller than the sum of its proper divisors (418473890305980).

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

221021100020100 is a wasteful number, since it uses less digits than its factorization.

221021100020100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8380509 (or 8380502 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 221021100020100 its reverse (1020001120122), we get a palindrome (222041101140222).

The spelling of 221021100020100 in words is "two hundred twenty-one trillion, twenty-one billion, one hundred million, twenty thousand, one hundred".