21335171317 has 2 divisors, whose sum is σ = 21335171318. Its totient is φ = 21335171316.

The previous prime is 21335171303. The next prime is 21335171321. The reversal of 21335171317 is 71317153312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18528926641 + 2806244676 = 136121^2 + 52974^2 .

It is a cyclic number.

It is not a de Polignac number, because 21335171317 - 2¹⁵ = 21335138549 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21335121317) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10667585658 + 10667585659.

It is an arithmetic number, because the mean of its divisors is an integer number (10667585659).

Almost surely, 2^21335171317 is an apocalyptic number.

It is an amenable number.

21335171317 is a deficient number, since it is larger than the sum of its proper divisors (1).

21335171317 is an equidigital number, since it uses as much as digits as its factorization.

21335171317 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13230, while the sum is 34.

The spelling of 21335171317 in words is "twenty-one billion, three hundred thirty-five million, one hundred seventy-one thousand, three hundred seventeen".