21010333221161 has 2 divisors, whose sum is σ = 21010333221162. Its totient is φ = 21010333221160.

The previous prime is 21010333221079. The next prime is 21010333221169. The reversal of 21010333221161 is 16112233301012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12460299907225 + 8550033313936 = 3529915^2 + 2924044^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21010333221161 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21010333221161.

It is not a weakly prime, because it can be changed into another prime (21010333221169) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10505166610580 + 10505166610581.

It is an arithmetic number, because the mean of its divisors is an integer number (10505166610581).

Almost surely, 2^{21010333221161} is an apocalyptic number.

It is an amenable number.

21010333221161 is a deficient number, since it is larger than the sum of its proper divisors (1).

21010333221161 is an equidigital number, since it uses as much as digits as its factorization.

21010333221161 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1296, while the sum is 26.

Adding to 21010333221161 its reverse (16112233301012), we get a palindrome (37122566522173).

The spelling of 21010333221161 in words is "twenty-one trillion, ten billion, three hundred thirty-three million, two hundred twenty-one thousand, one hundred sixty-one".