7667681778 has 56 divisors (see below), whose sum is σ = 17487510336. Its totient is φ = 2519861400.

The previous prime is 7667681731. The next prime is 7667681779. The reversal of 7667681778 is 8771867667.

It is not an unprimeable number, because it can be changed into a prime (7667681779) by changing a digit.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 66483 + ... + 140553.

Almost surely, 2^7667681778 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 7667681778, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8743755168).

7667681778 is an abundant number, since it is smaller than the sum of its proper divisors (9819828558).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

7667681778 is an equidigital number, since it uses as much as digits as its factorization.

7667681778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74162 (or 74147 counting only the distinct ones).

The product of its digits is 33191424, while the sum is 63.

The square root of 7667681778 is about 87565.3000794264. The cubic root of 7667681778 is about 1971.9142565308.

The spelling of 7667681778 in words is "seven billion, six hundred sixty-seven million, six hundred eighty-one thousand, seven hundred seventy-eight".