66777678 has 24 divisors (see below), whose sum is σ = 157838616. Its totient is φ = 20235600.

The previous prime is 66777661. The next prime is 66777703. The reversal of 66777678 is 87677766.

It is a happy number.

It is a super-3 number, since 3×66777678³ (a number of 24 digits) contains 333 as substring.

It is a congruent number.

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 11 ways as a sum of consecutive naturals, for example, 168433 + ... + 168828.

It is an arithmetic number, because the mean of its divisors is an integer number (6576609).

Almost surely, 2^66777678 is an apocalyptic number.

66777678 is an abundant number, since it is smaller than the sum of its proper divisors (91060938).

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

66777678 is a wasteful number, since it uses less digits than its factorization.

66777678 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 337280 (or 337277 counting only the distinct ones).

The product of its digits is 4148928, while the sum is 54.

The square root of 66777678 is about 8171.7610097212. The cubic root of 66777678 is about 405.7050726812.

The spelling of 66777678 in words is "sixty-six million, seven hundred seventy-seven thousand, six hundred seventy-eight".