766987778 has 6 divisors (see below), whose sum is σ = 1150540419. Its totient is φ = 383474306.

The previous prime is 766987777. The next prime is 766987789. The reversal of 766987778 is 877789667.

766987778 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 383493889 + 383493889 = 19583^2 + 19583^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=19583.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (766987777) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 29375 + ... + 48957.

Almost surely, 2^766987778 is an apocalyptic number.

766987778 is a deficient number, since it is larger than the sum of its proper divisors (383552641).

766987778 is an frugal number, since it uses more digits than its factorization.

766987778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39168 (or 19585 counting only the distinct ones).

The product of its digits is 49787136, while the sum is 65.

The square root of 766987778 is about 27694.5441919523. The cubic root of 766987778 is about 915.3688890532.

The spelling of 766987778 in words is "seven hundred sixty-six million, nine hundred eighty-seven thousand, seven hundred seventy-eight".