6777557557 has 2 divisors, whose sum is σ = 6777557558. Its totient is φ = 6777557556.

The previous prime is 6777557417. The next prime is 6777557587. The reversal of 6777557557 is 7557557776.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3825917316 + 2951640241 = 61854^2 + 54329^2 .

It is a cyclic number.

It is not a de Polignac number, because 6777557557 - 2¹¹ = 6777555509 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 6777557495 and 6777557504.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6777557587) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3388778778 + 3388778779.

It is an arithmetic number, because the mean of its divisors is an integer number (3388778779).

Almost surely, 2^6777557557 is an apocalyptic number.

It is an amenable number.

6777557557 is a deficient number, since it is larger than the sum of its proper divisors (1).

6777557557 is an equidigital number, since it uses as much as digits as its factorization.

6777557557 is an evil number, because the sum of its binary digits is even.

The product of its digits is 63026250, while the sum is 61.

The square root of 6777557557 is about 82325.9227521927. The cubic root of 6777557557 is about 1892.4499602683.

The spelling of 6777557557 in words is "six billion, seven hundred seventy-seven million, five hundred fifty-seven thousand, five hundred fifty-seven".