77985258977 has 4 divisors (see below), whose sum is σ = 78757390356. Its totient is φ = 77213127600.

The previous prime is 77985258943. The next prime is 77985258991.

77985258977 is nontrivially palindromic in base 10.

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

It can be written as a sum of positive squares in 2 ways, for example, as 35242177441 + 42743081536 = 187729^2 + 206744^2 .

It is a cyclic number.

It is not a de Polignac number, because 77985258977 - 2¹⁰ = 77985257953 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (77985258577) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 386065538 + ... + 386065739.

It is an arithmetic number, because the mean of its divisors is an integer number (19689347589).

Almost surely, 2^77985258977 is an apocalyptic number.

It is an amenable number.

77985258977 is a deficient number, since it is larger than the sum of its proper divisors (772131379).

77985258977 is a wasteful number, since it uses less digits than its factorization.

77985258977 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 772131378.

The product of its digits is 622339200, while the sum is 74.

The spelling of 77985258977 in words is "seventy-seven billion, nine hundred eighty-five million, two hundred fifty-eight thousand, nine hundred seventy-seven".