20555546657 has 2 divisors, whose sum is σ = 20555546658. Its totient is φ = 20555546656.

The previous prime is 20555546603. The next prime is 20555546717. The reversal of 20555546657 is 75664555502.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13532436241 + 7023110416 = 116329^2 + 83804^2 .

It is a cyclic number.

It is not a de Polignac number, because 20555546657 - 2⁶ = 20555546593 is a prime.

It is not a weakly prime, because it can be changed into another prime (20555536657) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10277773328 + 10277773329.

It is an arithmetic number, because the mean of its divisors is an integer number (10277773329).

Almost surely, 2^20555546657 is an apocalyptic number.

It is an amenable number.

20555546657 is a deficient number, since it is larger than the sum of its proper divisors (1).

20555546657 is an equidigital number, since it uses as much as digits as its factorization.

20555546657 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6300000, while the sum is 50.

The spelling of 20555546657 in words is "twenty billion, five hundred fifty-five million, five hundred forty-six thousand, six hundred fifty-seven".