66788766 has 64 divisors (see below), whose sum is σ = 162950400. Its totient is φ = 20109600.

The previous prime is 66788753. The next prime is 66788783.

66788766 is nontrivially palindromic in base 10.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 135781 + ... + 136271.

It is an arithmetic number, because the mean of its divisors is an integer number (2546100).

Almost surely, 2^66788766 is an apocalyptic number.

66788766 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 66788766, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (81475200).

66788766 is an abundant number, since it is smaller than the sum of its proper divisors (96161634).

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

66788766 is a wasteful number, since it uses less digits than its factorization.

66788766 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 742 (or 736 counting only the distinct ones).

The product of its digits is 4064256, while the sum is 54.

The square root of 66788766 is about 8172.4394154989. The cubic root of 66788766 is about 405.7275263365.

The spelling of 66788766 in words is "sixty-six million, seven hundred eighty-eight thousand, seven hundred sixty-six".