21804840713317 has 2 divisors, whose sum is σ = 21804840713318. Its totient is φ = 21804840713316.

The previous prime is 21804840713311. The next prime is 21804840713377. The reversal of 21804840713317 is 71331704840812.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12150341518756 + 9654499194561 = 3485734^2 + 3107169^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21804840713317 is a prime.

It is a super-2 number, since 2×21804840713317² (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 (21804840713311) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10902420356658 + 10902420356659.

It is an arithmetic number, because the mean of its divisors is an integer number (10902420356659).

Almost surely, 2^{21804840713317} is an apocalyptic number.

It is an amenable number.

21804840713317 is a deficient number, since it is larger than the sum of its proper divisors (1).

21804840713317 is an equidigital number, since it uses as much as digits as its factorization.

21804840713317 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 903168, while the sum is 49.

The spelling of 21804840713317 in words is "twenty-one trillion, eight hundred four billion, eight hundred forty million, seven hundred thirteen thousand, three hundred seventeen".