66876778 has 16 divisors (see below), whose sum is σ = 106655616. Its totient is φ = 31379920.

The previous prime is 66876769. The next prime is 66876791. The reversal of 66876778 is 87767866.

It is a happy number.

It is a super-2 number, since 2×66876778² = 8945006871322568, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11278 + ... + 16153.

It is an arithmetic number, because the mean of its divisors is an integer number (6665976).

Almost surely, 2^66876778 is an apocalyptic number.

66876778 is a deficient number, since it is larger than the sum of its proper divisors (39778838).

66876778 is a wasteful number, since it uses less digits than its factorization.

66876778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27509.

The product of its digits is 4741632, while the sum is 55.

The square root of 66876778 is about 8177.8223262675. The cubic root of 66876778 is about 405.9056661611.

The spelling of 66876778 in words is "sixty-six million, eight hundred seventy-six thousand, seven hundred seventy-eight".