221100020021 has 16 divisors (see below), whose sum is σ = 233647545600. Its totient is φ = 208645056000.

The previous prime is 221100020017. The next prime is 221100020047. The reversal of 221100020021 is 120020001122.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 221100020021 - 2² = 221100020017 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221100019984 and 221100020011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221100020051) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5457881 + ... + 5498241.

It is an arithmetic number, because the mean of its divisors is an integer number (14602971600).

Almost surely, 2^221100020021 is an apocalyptic number.

It is an amenable number.

221100020021 is a deficient number, since it is larger than the sum of its proper divisors (12547525579).

221100020021 is a wasteful number, since it uses less digits than its factorization.

221100020021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41500.

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 221100020021 its reverse (120020001122), we get a palindrome (341120021143).

The spelling of 221100020021 in words is "two hundred twenty-one billion, one hundred million, twenty thousand, twenty-one".