66777609 has 16 divisors (see below), whose sum is σ = 94049280. Its totient is φ = 42028560.

The previous prime is 66777589. The next prime is 66777617. The reversal of 66777609 is 90677766.

It is not a de Polignac number, because 66777609 - 2⁵ = 66777577 is a prime.

It is a super-3 number, since 3×66777609³ (a number of 24 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (66777619) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15844 + ... + 19610.

It is an arithmetic number, because the mean of its divisors is an integer number (5878080).

Almost surely, 2^66777609 is an apocalyptic number.

It is an amenable number.

66777609 is a deficient number, since it is larger than the sum of its proper divisors (27271671).

66777609 is a wasteful number, since it uses less digits than its factorization.

66777609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4100.

The product of its (nonzero) digits is 666792, while the sum is 48.

The square root of 66777609 is about 8171.7567878639. The cubic root of 66777609 is about 405.7049329456.

The spelling of 66777609 in words is "sixty-six million, seven hundred seventy-seven thousand, six hundred nine".