21120221122061 has 2 divisors, whose sum is σ = 21120221122062. Its totient is φ = 21120221122060.

The previous prime is 21120221121977. The next prime is 21120221122067. The reversal of 21120221122061 is 16022112202112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16565966357161 + 4554254764900 = 4070131^2 + 2134070^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21120221122061 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21120221122067) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10560110561030 + 10560110561031.

It is an arithmetic number, because the mean of its divisors is an integer number (10560110561031).

Almost surely, 2^{21120221122061} is an apocalyptic number.

It is an amenable number.

21120221122061 is a deficient number, since it is larger than the sum of its proper divisors (1).

21120221122061 is an equidigital number, since it uses as much as digits as its factorization.

21120221122061 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 384, while the sum is 23.

Adding to 21120221122061 its reverse (16022112202112), we get a palindrome (37142333324173).

The spelling of 21120221122061 in words is "twenty-one trillion, one hundred twenty billion, two hundred twenty-one million, one hundred twenty-two thousand, sixty-one".