20559100777 has 2 divisors, whose sum is σ = 20559100778. Its totient is φ = 20559100776.

The previous prime is 20559100759. The next prime is 20559100787. The reversal of 20559100777 is 77700195502.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20340179161 + 218921616 = 142619^2 + 14796^2 .

It is a cyclic number.

It is not a de Polignac number, because 20559100777 - 2²⁷ = 20424883049 is a prime.

It is not a weakly prime, because it can be changed into another prime (20559100787) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10279550388 + 10279550389.

It is an arithmetic number, because the mean of its divisors is an integer number (10279550389).

Almost surely, 2^20559100777 is an apocalyptic number.

It is an amenable number.

20559100777 is a deficient number, since it is larger than the sum of its proper divisors (1).

20559100777 is an equidigital number, since it uses as much as digits as its factorization.

20559100777 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 154350, while the sum is 43.

The spelling of 20559100777 in words is "twenty billion, five hundred fifty-nine million, one hundred thousand, seven hundred seventy-seven".