221100221021 has 2 divisors, whose sum is σ = 221100221022. Its totient is φ = 221100221020.

The previous prime is 221100220981. The next prime is 221100221053. The reversal of 221100221021 is 120122001122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 188777215225 + 32323005796 = 434485^2 + 179786^2 .

It is a cyclic number.

It is not a de Polignac number, because 221100221021 - 2²² = 221096026717 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 221100220987 and 221100221005.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221100221071) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110550110510 + 110550110511.

It is an arithmetic number, because the mean of its divisors is an integer number (110550110511).

Almost surely, 2^221100221021 is an apocalyptic number.

It is an amenable number.

221100221021 is a deficient number, since it is larger than the sum of its proper divisors (1).

221100221021 is an equidigital number, since it uses as much as digits as its factorization.

221100221021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 221100221021 its reverse (120122001122), we get a palindrome (341222222143).

The spelling of 221100221021 in words is "two hundred twenty-one billion, one hundred million, two hundred twenty-one thousand, twenty-one".