6778751961 has 16 divisors (see below), whose sum is σ = 9522555200. Its totient is φ = 4277484288.

The previous prime is 6778751897. The next prime is 6778751963. The reversal of 6778751961 is 1691578776.

It is a happy number.

It is not a de Polignac number, because 6778751961 - 2⁶ = 6778751897 is a prime.

It is a super-2 number, since 2×6778751961² = 91902956297522691042, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (57).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6778751963) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11685 + ... + 117021.

It is an arithmetic number, because the mean of its divisors is an integer number (595159700).

Almost surely, 2^6778751961 is an apocalyptic number.

It is an amenable number.

6778751961 is a deficient number, since it is larger than the sum of its proper divisors (2743803239).

6778751961 is a wasteful number, since it uses less digits than its factorization.

6778751961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106488.

The product of its digits is 4445280, while the sum is 57.

The square root of 6778751961 is about 82333.1765511328. The cubic root of 6778751961 is about 1892.5611220950.

The spelling of 6778751961 in words is "six billion, seven hundred seventy-eight million, seven hundred fifty-one thousand, nine hundred sixty-one".