221100220022021 has 8 divisors (see below), whose sum is σ = 234769305452184. Its totient is φ = 207504822384640.

The previous prime is 221100220022009. The next prime is 221100220022053. The reversal of 221100220022021 is 120220022001122.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 59584334989921 + 161515885032100 = 7719089^2 + 12708890^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 221100220022021 - 2⁶ = 221100220021957 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221100220022081) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18421942010 + ... + 18421954011.

It is an arithmetic number, because the mean of its divisors is an integer number (29346163181523).

Almost surely, 2^{221100220022021} is an apocalyptic number.

It is an amenable number.

221100220022021 is a deficient number, since it is larger than the sum of its proper divisors (13669085430163).

221100220022021 is a wasteful number, since it uses less digits than its factorization.

221100220022021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36843896391.

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 221100220022021 its reverse (120220022001122), we get a palindrome (341320242023143).

The spelling of 221100220022021 in words is "two hundred twenty-one trillion, one hundred billion, two hundred twenty million, twenty-two thousand, twenty-one".