7971238509777 has 12 divisors (see below), whose sum is σ = 11546628780804. Its totient is φ = 5299104729600.

The previous prime is 7971238509721. The next prime is 7971238509833. The reversal of 7971238509777 is 7779058321797.

7971238509777 is a `hidden beast` number, since 7 + 9 + 7 + 12 + 38 + 509 + 7 + 77 = 666.

It is an interprime number because it is at equal distance from previous prime (7971238509721) and next prime (7971238509833).

It can be written as a sum of positive squares in 2 ways, for example, as 1279683575361 + 6691554934416 = 1131231^2 + 2586804^2 .

It is not a de Polignac number, because 7971238509777 - 2⁷ = 7971238509649 is a prime.

It is a super-4 number, since 4×7971238509777⁴ (a number of 53 digits) contains 4444 as substring.

It is not an unprimeable number, because it can be changed into a prime (7971238509077) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1254519724 + ... + 1254526077.

It is an arithmetic number, because the mean of its divisors is an integer number (962219065067).

Almost surely, 2^{7971238509777} is an apocalyptic number.

It is an amenable number.

7971238509777 is a deficient number, since it is larger than the sum of its proper divisors (3575390271027).

7971238509777 is a wasteful number, since it uses less digits than its factorization.

7971238509777 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2509046160 (or 2509046157 counting only the distinct ones).

The product of its (nonzero) digits is 326728080, while the sum is 72.

The spelling of 7971238509777 in words is "seven trillion, nine hundred seventy-one billion, two hundred thirty-eight million, five hundred nine thousand, seven hundred seventy-seven".