77800550657 has 2 divisors, whose sum is σ = 77800550658. Its totient is φ = 77800550656.

The previous prime is 77800550557. The next prime is 77800550671. The reversal of 77800550657 is 75605500877.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 42732744961 + 35067805696 = 206719^2 + 187264^2 .

It is a cyclic number.

It is not a de Polignac number, because 77800550657 - 2¹⁰ = 77800549633 is a prime.

It is a super-3 number, since 3×77800550657³ (a number of 34 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (77800550557) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38900275328 + 38900275329.

It is an arithmetic number, because the mean of its divisors is an integer number (38900275329).

Almost surely, 2^77800550657 is an apocalyptic number.

It is an amenable number.

77800550657 is a deficient number, since it is larger than the sum of its proper divisors (1).

77800550657 is an equidigital number, since it uses as much as digits as its factorization.

77800550657 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2058000, while the sum is 50.

The spelling of 77800550657 in words is "seventy-seven billion, eight hundred million, five hundred fifty thousand, six hundred fifty-seven".