66777760 has 96 divisors (see below), whose sum is σ = 182286720. Its totient is φ = 22643712.

The previous prime is 66777713. The next prime is 66777779. The reversal of 66777760 is 6777766.

It is a self number, because there is not a number n which added to its sum of digits gives 66777760.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 121807 + ... + 122353.

It is an arithmetic number, because the mean of its divisors is an integer number (1898820).

Almost surely, 2^66777760 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66777760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (91143360).

66777760 is an abundant number, since it is smaller than the sum of its proper divisors (115508960).

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

66777760 is a wasteful number, since it uses less digits than its factorization.

66777760 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 678 (or 670 counting only the distinct ones).

The product of its (nonzero) digits is 518616, while the sum is 46.

The square root of 66777760 is about 8171.7660269981. The cubic root of 66777760 is about 405.7052387437.

The spelling of 66777760 in words is "sixty-six million, seven hundred seventy-seven thousand, seven hundred sixty".