21112222200221 has 2 divisors, whose sum is σ = 21112222200222. Its totient is φ = 21112222200220.

The previous prime is 21112222200217. The next prime is 21112222200241. The reversal of 21112222200221 is 12200222221112.

It is an a-pointer prime, because the next prime (21112222200241) can be obtained adding 21112222200221 to its sum of digits (20).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19158251556196 + 1953970644025 = 4377014^2 + 1397845^2 .

It is a cyclic number.

It is not a de Polignac number, because 21112222200221 - 2² = 21112222200217 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 = 21112222200193 and 21112222200202.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21112222200241) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10556111100110 + 10556111100111.

It is an arithmetic number, because the mean of its divisors is an integer number (10556111100111).

Almost surely, 2^{21112222200221} is an apocalyptic number.

It is an amenable number.

21112222200221 is a deficient number, since it is larger than the sum of its proper divisors (1).

21112222200221 is an equidigital number, since it uses as much as digits as its factorization.

21112222200221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 256, while the sum is 20.

Adding to 21112222200221 its reverse (12200222221112), we get a palindrome (33312444421333).

The spelling of 21112222200221 in words is "twenty-one trillion, one hundred twelve billion, two hundred twenty-two million, two hundred thousand, two hundred twenty-one".