7686543778 has 16 divisors (see below), whose sum is σ = 12390253344. Its totient is φ = 3563208000.

The previous prime is 7686543773. The next prime is 7686543779. The reversal of 7686543778 is 8773456867.

It is a happy number.

It is a super-2 number, since 2×7686543778² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (7686543773) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1684848 + ... + 1689403.

It is an arithmetic number, because the mean of its divisors is an integer number (774390834).

Almost surely, 2^7686543778 is an apocalyptic number.

7686543778 is a deficient number, since it is larger than the sum of its proper divisors (4703709566).

7686543778 is a wasteful number, since it uses less digits than its factorization.

7686543778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3374337.

The product of its digits is 47416320, while the sum is 61.

The square root of 7686543778 is about 87672.9364057119. The cubic root of 7686543778 is about 1973.5298595651.

The spelling of 7686543778 in words is "seven billion, six hundred eighty-six million, five hundred forty-three thousand, seven hundred seventy-eight".