7977709798655 has 4 divisors (see below), whose sum is σ = 9573251758392. Its totient is φ = 6382167838920.

The previous prime is 7977709798571. The next prime is 7977709798727. The reversal of 7977709798655 is 5568979077797.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 7977709798655 - 2¹⁴ = 7977709782271 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 797770979861 + ... + 797770979870.

It is an arithmetic number, because the mean of its divisors is an integer number (2393312939598).

Almost surely, 2^{7977709798655} is an apocalyptic number.

7977709798655 is a deficient number, since it is larger than the sum of its proper divisors (1595541959737).

7977709798655 is a wasteful number, since it uses less digits than its factorization.

7977709798655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1595541959736.

The product of its (nonzero) digits is 14702763600, while the sum is 86.

The spelling of 7977709798655 in words is "seven trillion, nine hundred seventy-seven billion, seven hundred nine million, seven hundred ninety-eight thousand, six hundred fifty-five".