66666766 has 8 divisors (see below), whose sum is σ = 103448520. Its totient is φ = 32183928.

The previous prime is 66666751. The next prime is 66666781. The reversal of 66666766 is 66766666.

It is a happy number.

66666766 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (66666751) and next prime (66666781).

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 574656 + ... + 574771.

It is an arithmetic number, because the mean of its divisors is an integer number (12931065).

Almost surely, 2^66666766 is an apocalyptic number.

66666766 is a deficient number, since it is larger than the sum of its proper divisors (36781754).

66666766 is a wasteful number, since it uses less digits than its factorization.

66666766 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1149458.

The product of its digits is 1959552, while the sum is 49.

The square root of 66666766 is about 8164.9718921745. The cubic root of 66666766 is about 405.4803344266.

The spelling of 66666766 in words is "sixty-six million, six hundred sixty-six thousand, seven hundred sixty-six".