21202102202117 has 2 divisors, whose sum is σ = 21202102202118. Its totient is φ = 21202102202116.

The previous prime is 21202102202087. The next prime is 21202102202159. The reversal of 21202102202117 is 71120220120212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12896817993796 + 8305284208321 = 3591214^2 + 2881889^2 .

It is a cyclic number.

It is not a de Polignac number, because 21202102202117 - 2²⁴ = 21202085424901 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21202102202092 and 21202102202101.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21202102202317) 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, 10601051101058 + 10601051101059.

It is an arithmetic number, because the mean of its divisors is an integer number (10601051101059).

Almost surely, 2^{21202102202117} is an apocalyptic number.

It is an amenable number.

21202102202117 is a deficient number, since it is larger than the sum of its proper divisors (1).

21202102202117 is an equidigital number, since it uses as much as digits as its factorization.

21202102202117 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 448, while the sum is 23.

Adding to 21202102202117 its reverse (71120220120212), we get a palindrome (92322322322329).

The spelling of 21202102202117 in words is "twenty-one trillion, two hundred two billion, one hundred two million, two hundred two thousand, one hundred seventeen".