66777716 has 12 divisors (see below), whose sum is σ = 117194532. Its totient is φ = 33293568.

The previous prime is 66777713. The next prime is 66777779. The reversal of 66777716 is 61777766.

It can be written as a sum of positive squares in 2 ways, for example, as 31967716 + 34810000 = 5654^2 + 5900^2 .

It is a super-3 number, since 3×66777716³ (a number of 24 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66777713) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 22235 + ... + 25058.

It is an arithmetic number, because the mean of its divisors is an integer number (9766211).

Almost surely, 2^66777716 is an apocalyptic number.

It is an amenable number.

66777716 is a deficient number, since it is larger than the sum of its proper divisors (50416816).

66777716 is a wasteful number, since it uses less digits than its factorization.

66777716 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47650 (or 47648 counting only the distinct ones).

The product of its digits is 518616, while the sum is 47.

The square root of 66777716 is about 8171.7633348011. The cubic root of 66777716 is about 405.7051496370.

The spelling of 66777716 in words is "sixty-six million, seven hundred seventy-seven thousand, seven hundred sixteen".