21113317 has 2 divisors, whose sum is σ = 21113318. Its totient is φ = 21113316.

The previous prime is 21113299. The next prime is 21113329. The reversal of 21113317 is 71331112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10962721 + 10150596 = 3311^2 + 3186^2 .

It is a cyclic number.

It is not a de Polignac number, because 21113317 - 2¹⁹ = 20589029 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21113294 and 21113303.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21113357) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10556658 + 10556659.

It is an arithmetic number, because the mean of its divisors is an integer number (10556659).

Almost surely, 2^21113317 is an apocalyptic number.

It is an amenable number.

21113317 is a deficient number, since it is larger than the sum of its proper divisors (1).

21113317 is an equidigital number, since it uses as much as digits as its factorization.

21113317 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 126, while the sum is 19.

The square root of 21113317 is about 4594.9229590930. The cubic root of 21113317 is about 276.3877705954.

Adding to 21113317 its reverse (71331112), we get a palindrome (92444429).

The spelling of 21113317 in words is "twenty-one million, one hundred thirteen thousand, three hundred seventeen".