20576538685217 has 2 divisors, whose sum is σ = 20576538685218. Its totient is φ = 20576538685216.

The previous prime is 20576538685139. The next prime is 20576538685259. The reversal of 20576538685217 is 71258683567502.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17183313116176 + 3393225569041 = 4145276^2 + 1842071^2 .

It is a cyclic number.

It is not a de Polignac number, because 20576538685217 - 2²² = 20576534490913 is a prime.

It is not a weakly prime, because it can be changed into another prime (20576538685267) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10288269342608 + 10288269342609.

It is an arithmetic number, because the mean of its divisors is an integer number (10288269342609).

Almost surely, 2^{20576538685217} is an apocalyptic number.

It is an amenable number.

20576538685217 is a deficient number, since it is larger than the sum of its proper divisors (1).

20576538685217 is an equidigital number, since it uses as much as digits as its factorization.

20576538685217 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 169344000, while the sum is 65.

The spelling of 20576538685217 in words is "twenty trillion, five hundred seventy-six billion, five hundred thirty-eight million, six hundred eighty-five thousand, two hundred seventeen".