21113002517 has 2 divisors, whose sum is σ = 21113002518. Its totient is φ = 21113002516.

The previous prime is 21113002489. The next prime is 21113002541. The reversal of 21113002517 is 71520031112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12275310436 + 8837692081 = 110794^2 + 94009^2 .

It is a cyclic number.

It is not a de Polignac number, because 21113002517 - 2¹⁸ = 21112740373 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21113002492 and 21113002501.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21113001517) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10556501258 + 10556501259.

It is an arithmetic number, because the mean of its divisors is an integer number (10556501259).

Almost surely, 2^21113002517 is an apocalyptic number.

It is an amenable number.

21113002517 is a deficient number, since it is larger than the sum of its proper divisors (1).

21113002517 is an equidigital number, since it uses as much as digits as its factorization.

21113002517 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 420, while the sum is 23.

Adding to 21113002517 its reverse (71520031112), we get a palindrome (92633033629).

The spelling of 21113002517 in words is "twenty-one billion, one hundred thirteen million, two thousand, five hundred seventeen".