6778151991 has 48 divisors (see below), whose sum is σ = 11549079360. Its totient is φ = 3790402560.

The previous prime is 6778151977. The next prime is 6778152061. The reversal of 6778151991 is 1991518776.

It is not a de Polignac number, because 6778151991 - 2¹⁸ = 6777889847 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6778151921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1075 + ... + 116436.

It is an arithmetic number, because the mean of its divisors is an integer number (240605820).

Almost surely, 2^6778151991 is an apocalyptic number.

6778151991 is a deficient number, since it is larger than the sum of its proper divisors (4770927369).

6778151991 is a wasteful number, since it uses less digits than its factorization.

6778151991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 117576 (or 117573 counting only the distinct ones).

The product of its digits is 952560, while the sum is 54.

The square root of 6778151991 is about 82329.5329210606. The cubic root of 6778151991 is about 1892.5052851994.

The spelling of 6778151991 in words is "six billion, seven hundred seventy-eight million, one hundred fifty-one thousand, nine hundred ninety-one".