21216363361117 has 2 divisors, whose sum is σ = 21216363361118. Its totient is φ = 21216363361116.

The previous prime is 21216363361093. The next prime is 21216363361121. The reversal of 21216363361117 is 71116336361212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21015797321401 + 200566039716 = 4584299^2 + 447846^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21216363361117 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21216363361157) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10608181680558 + 10608181680559.

It is an arithmetic number, because the mean of its divisors is an integer number (10608181680559).

Almost surely, 2^{21216363361117} is an apocalyptic number.

It is an amenable number.

21216363361117 is a deficient number, since it is larger than the sum of its proper divisors (1).

21216363361117 is an equidigital number, since it uses as much as digits as its factorization.

21216363361117 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 163296, while the sum is 43.

The spelling of 21216363361117 in words is "twenty-one trillion, two hundred sixteen billion, three hundred sixty-three million, three hundred sixty-one thousand, one hundred seventeen".