77778288009 has 6 divisors (see below), whose sum is σ = 112346416026. Its totient is φ = 51852192000.

The previous prime is 77778287879. The next prime is 77778288011. The reversal of 77778288009 is 90088287777.

It can be written as a sum of positive squares in only one way, i.e., 39842156025 + 37936131984 = 199605^2 + 194772^2 .

It is not a de Polignac number, because 77778288009 - 2²⁷ = 77644070281 is a prime.

It is a super-2 number, since 2×77778288009² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (77778280009) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4321015992 + ... + 4321016009.

It is an arithmetic number, because the mean of its divisors is an integer number (18724402671).

Almost surely, 2^77778288009 is an apocalyptic number.

It is an amenable number.

77778288009 is a deficient number, since it is larger than the sum of its proper divisors (34568128017).

77778288009 is a wasteful number, since it uses less digits than its factorization.

77778288009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8642032007 (or 8642032004 counting only the distinct ones).

The product of its (nonzero) digits is 22127616, while the sum is 63.

The spelling of 77778288009 in words is "seventy-seven billion, seven hundred seventy-eight million, two hundred eighty-eight thousand, nine".