20620620666617 has 2 divisors, whose sum is σ = 20620620666618. Its totient is φ = 20620620666616.

The previous prime is 20620620666599. The next prime is 20620620666671. The reversal of 20620620666617 is 71666602602602.

Together with next prime (20620620666671) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17712490721641 + 2908129944976 = 4208621^2 + 1705324^2 .

It is a cyclic number.

It is not a de Polignac number, because 20620620666617 - 2²⁰ = 20620619618041 is a prime.

It is not a weakly prime, because it can be changed into another prime (20620620666517) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10310310333308 + 10310310333309.

It is an arithmetic number, because the mean of its divisors is an integer number (10310310333309).

Almost surely, 2^{20620620666617} is an apocalyptic number.

It is an amenable number.

20620620666617 is a deficient number, since it is larger than the sum of its proper divisors (1).

20620620666617 is an equidigital number, since it uses as much as digits as its factorization.

20620620666617 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2612736, while the sum is 50.

The spelling of 20620620666617 in words is "twenty trillion, six hundred twenty billion, six hundred twenty million, six hundred sixty-six thousand, six hundred seventeen".