20001222161 has 2 divisors, whose sum is σ = 20001222162. Its totient is φ = 20001222160.

The previous prime is 20001222149. The next prime is 20001222217. The reversal of 20001222161 is 16122210002.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16285588225 + 3715633936 = 127615^2 + 60956^2 .

It is a cyclic number.

It is not a de Polignac number, because 20001222161 - 2¹⁰ = 20001221137 is a prime.

It is not a weakly prime, because it can be changed into another prime (20001227161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10000611080 + 10000611081.

It is an arithmetic number, because the mean of its divisors is an integer number (10000611081).

Almost surely, 2^20001222161 is an apocalyptic number.

It is an amenable number.

20001222161 is a deficient number, since it is larger than the sum of its proper divisors (1).

20001222161 is an equidigital number, since it uses as much as digits as its factorization.

20001222161 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 96, while the sum is 17.

Adding to 20001222161 its reverse (16122210002), we get a palindrome (36123432163).

The spelling of 20001222161 in words is "twenty billion, one million, two hundred twenty-two thousand, one hundred sixty-one".