20002122221 has 2 divisors, whose sum is σ = 20002122222. Its totient is φ = 20002122220.

The previous prime is 20002122211. The next prime is 20002122233. The reversal of 20002122221 is 12222120002.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19603920196 + 398202025 = 140014^2 + 19955^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20002122221 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 = 20002122196 and 20002122205.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20002122211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10001061110 + 10001061111.

It is an arithmetic number, because the mean of its divisors is an integer number (10001061111).

Almost surely, 2^20002122221 is an apocalyptic number.

It is an amenable number.

20002122221 is a deficient number, since it is larger than the sum of its proper divisors (1).

20002122221 is an equidigital number, since it uses as much as digits as its factorization.

20002122221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 64, while the sum is 14.

Adding to 20002122221 its reverse (12222120002), we get a palindrome (32224242223).

It can be divided in two parts, 20002 and 122221, that multiplied together give a palindrome (2444664442).

The spelling of 20002122221 in words is "twenty billion, two million, one hundred twenty-two thousand, two hundred twenty-one".