20011222111121 has 2 divisors, whose sum is σ = 20011222111122. Its totient is φ = 20011222111120.

The previous prime is 20011222111103. The next prime is 20011222111147. The reversal of 20011222111121 is 12111122211002.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14992887364225 + 5018334746896 = 3872065^2 + 2240164^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20011222111121 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20011222111121.

It is not a weakly prime, because it can be changed into another prime (20011222111921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10005611055560 + 10005611055561.

It is an arithmetic number, because the mean of its divisors is an integer number (10005611055561).

Almost surely, 2^{20011222111121} is an apocalyptic number.

It is an amenable number.

20011222111121 is a deficient number, since it is larger than the sum of its proper divisors (1).

20011222111121 is an equidigital number, since it uses as much as digits as its factorization.

20011222111121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 20011222111121 its reverse (12111122211002), we get a palindrome (32122344322123).

The spelling of 20011222111121 in words is "twenty trillion, eleven billion, two hundred twenty-two million, one hundred eleven thousand, one hundred twenty-one".