7985077777 has 2 divisors, whose sum is σ = 7985077778. Its totient is φ = 7985077776.

The previous prime is 7985077729. The next prime is 7985077799. The reversal of 7985077777 is 7777705897.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6870586321 + 1114491456 = 82889^2 + 33384^2 .

It is a cyclic number.

It is not a de Polignac number, because 7985077777 - 2⁷ = 7985077649 is a prime.

It is a super-2 number, since 2×7985077777² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (7985077717) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3992538888 + 3992538889.

It is an arithmetic number, because the mean of its divisors is an integer number (3992538889).

Almost surely, 2^7985077777 is an apocalyptic number.

It is an amenable number.

7985077777 is a deficient number, since it is larger than the sum of its proper divisors (1).

7985077777 is an equidigital number, since it uses as much as digits as its factorization.

7985077777 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 42353640, while the sum is 64.

The square root of 7985077777 is about 89359.2624018350. The cubic root of 7985077777 is about 1998.7557074452.

The spelling of 7985077777 in words is "seven billion, nine hundred eighty-five million, seventy-seven thousand, seven hundred seventy-seven".