21121221220193 has 2 divisors, whose sum is σ = 21121221220194. Its totient is φ = 21121221220192.

The previous prime is 21121221220163. The next prime is 21121221220241. The reversal of 21121221220193 is 39102212212112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16888951886689 + 4232269333504 = 4109617^2 + 2057248^2 .

It is a cyclic number.

It is not a de Polignac number, because 21121221220193 - 2⁸ = 21121221219937 is a prime.

It is a super-2 number, since 2×21121221220193² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21121221220163) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10560610610096 + 10560610610097.

It is an arithmetic number, because the mean of its divisors is an integer number (10560610610097).

Almost surely, 2^{21121221220193} is an apocalyptic number.

It is an amenable number.

21121221220193 is a deficient number, since it is larger than the sum of its proper divisors (1).

21121221220193 is an equidigital number, since it uses as much as digits as its factorization.

21121221220193 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1728, while the sum is 29.

The spelling of 21121221220193 in words is "twenty-one trillion, one hundred twenty-one billion, two hundred twenty-one million, two hundred twenty thousand, one hundred ninety-three".