21068689613 has 2 divisors, whose sum is σ = 21068689614. Its totient is φ = 21068689612.

The previous prime is 21068689601. The next prime is 21068689627. The reversal of 21068689613 is 31698686012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14357311684 + 6711377929 = 119822^2 + 81923^2 .

It is a cyclic number.

It is not a de Polignac number, because 21068689613 - 2⁸ = 21068689357 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21068689693) 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, 10534344806 + 10534344807.

It is an arithmetic number, because the mean of its divisors is an integer number (10534344807).

Almost surely, 2^21068689613 is an apocalyptic number.

It is an amenable number.

21068689613 is a deficient number, since it is larger than the sum of its proper divisors (1).

21068689613 is an equidigital number, since it uses as much as digits as its factorization.

21068689613 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 746496, while the sum is 50.

The spelling of 21068689613 in words is "twenty-one billion, sixty-eight million, six hundred eighty-nine thousand, six hundred thirteen".