20665256713 has 2 divisors, whose sum is σ = 20665256714. Its totient is φ = 20665256712.

The previous prime is 20665256669. The next prime is 20665256747. The reversal of 20665256713 is 31765256602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12150211984 + 8515044729 = 110228^2 + 92277^2 .

It is a cyclic number.

It is not a de Polignac number, because 20665256713 - 2¹⁷ = 20665125641 is a prime.

It is a super-3 number, since 3×20665256713³ (a number of 32 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20665256713.

It is not a weakly prime, because it can be changed into another prime (20665256753) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10332628356 + 10332628357.

It is an arithmetic number, because the mean of its divisors is an integer number (10332628357).

Almost surely, 2^20665256713 is an apocalyptic number.

It is an amenable number.

20665256713 is a deficient number, since it is larger than the sum of its proper divisors (1).

20665256713 is an equidigital number, since it uses as much as digits as its factorization.

20665256713 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 453600, while the sum is 43.

The spelling of 20665256713 in words is "twenty billion, six hundred sixty-five million, two hundred fifty-six thousand, seven hundred thirteen".