21364711257709 has 2 divisors, whose sum is σ = 21364711257710. Its totient is φ = 21364711257708.

The previous prime is 21364711257691. The next prime is 21364711257749. The reversal of 21364711257709 is 90775211746312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16286349853225 + 5078361404484 = 4035635^2 + 2253522^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21364711257709 is a prime.

It is a super-3 number, since 3×21364711257709³ (a number of 41 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a self number, because there is not a number n which added to its sum of digits gives 21364711257709.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21364711257749) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10682355628854 + 10682355628855.

It is an arithmetic number, because the mean of its divisors is an integer number (10682355628855).

Almost surely, 2^{21364711257709} is an apocalyptic number.

It is an amenable number.

21364711257709 is a deficient number, since it is larger than the sum of its proper divisors (1).

21364711257709 is an equidigital number, since it uses as much as digits as its factorization.

21364711257709 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4445280, while the sum is 55.

The spelling of 21364711257709 in words is "twenty-one trillion, three hundred sixty-four billion, seven hundred eleven million, two hundred fifty-seven thousand, seven hundred nine".