77118382991 has 4 divisors (see below), whose sum is σ = 83050566312. Its totient is φ = 71186199672.

The previous prime is 77118382987. The next prime is 77118382993. The reversal of 77118382991 is 19928381177.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19928381177 = 457 ⋅43606961.

It is a cyclic number.

It is not a de Polignac number, because 77118382991 - 2² = 77118382987 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77118382993) 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, 2966091641 + ... + 2966091666.

It is an arithmetic number, because the mean of its divisors is an integer number (20762641578).

Almost surely, 2^77118382991 is an apocalyptic number.

77118382991 is a deficient number, since it is larger than the sum of its proper divisors (5932183321).

77118382991 is a wasteful number, since it uses less digits than its factorization.

77118382991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5932183320.

The product of its digits is 1524096, while the sum is 56.

The spelling of 77118382991 in words is "seventy-seven billion, one hundred eighteen million, three hundred eighty-two thousand, nine hundred ninety-one".