266666778 has 24 divisors (see below), whose sum is σ = 660318048. Its totient is φ = 76190472.

The previous prime is 266666731. The next prime is 266666789. The reversal of 266666778 is 877666662.

266666778 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×266666778² = 142222340977802568, which contains 22 as substring.

It is a Curzon number.

It is a plaindrome in base 10.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1058076 + ... + 1058327.

It is an arithmetic number, because the mean of its divisors is an integer number (27513252).

Almost surely, 2^266666778 is an apocalyptic number.

266666778 is an abundant number, since it is smaller than the sum of its proper divisors (393651270).

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

266666778 is a wasteful number, since it uses less digits than its factorization.

266666778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2116418 (or 2116415 counting only the distinct ones).

The product of its digits is 6096384, while the sum is 54.

The square root of 266666778 is about 16329.9350274274. The cubic root of 266666778 is about 643.6596793130.

The spelling of 266666778 in words is "two hundred sixty-six million, six hundred sixty-six thousand, seven hundred seventy-eight".