21111021201181 has 2 divisors, whose sum is σ = 21111021201182. Its totient is φ = 21111021201180.

The previous prime is 21111021201169. The next prime is 21111021201271. The reversal of 21111021201181 is 18110212011112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17201341502500 + 3909679698681 = 4147450^2 + 1977291^2 .

It is a cyclic number.

It is not a de Polignac number, because 21111021201181 - 2⁹ = 21111021200669 is a prime.

It is a super-2 number, since 2×21111021201181² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21111021201121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10555510600590 + 10555510600591.

It is an arithmetic number, because the mean of its divisors is an integer number (10555510600591).

Almost surely, 2^{21111021201181} is an apocalyptic number.

It is an amenable number.

21111021201181 is a deficient number, since it is larger than the sum of its proper divisors (1).

21111021201181 is an equidigital number, since it uses as much as digits as its factorization.

21111021201181 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 64, while the sum is 22.

Adding to 21111021201181 its reverse (18110212011112), we get a palindrome (39221233212293).

The spelling of 21111021201181 in words is "twenty-one trillion, one hundred eleven billion, twenty-one million, two hundred one thousand, one hundred eighty-one".