2666778 has 8 divisors (see below), whose sum is σ = 5333568. Its totient is φ = 888924.

The previous prime is 2666749. The next prime is 2666779. The reversal of 2666778 is 8776662.

It is a sphenic number, since it is the product of 3 distinct primes.

2666778 is an admirable number.

It is a super-2 number, since 2×2666778² = 14223409802568, which contains 22 as substring.

It is a Curzon number.

It is a plaindrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (2666779) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 222226 + ... + 222237.

It is an arithmetic number, because the mean of its divisors is an integer number (666696).

2^2666778 is an apocalyptic number.

2666778 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

2666778 is a wasteful number, since it uses less digits than its factorization.

2666778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 444468.

The product of its digits is 169344, while the sum is 42.

The square root of 2666778 is about 1633.0272502319. The cubic root of 2666778 is about 138.6741846988.

The spelling of 2666778 in words is "two million, six hundred sixty-six thousand, seven hundred seventy-eight".