66808756 has 36 divisors (see below), whose sum is σ = 139183968. Its totient is φ = 27962928.

The previous prime is 66808747. The next prime is 66808757. The reversal of 66808756 is 65780866.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66808757) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4465 + ... + 12391.

Almost surely, 2^66808756 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 66808756, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (69591984).

66808756 is an abundant number, since it is smaller than the sum of its proper divisors (72375212).

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

66808756 is a wasteful number, since it uses less digits than its factorization.

66808756 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7988 (or 7979 counting only the distinct ones).

The product of its (nonzero) digits is 483840, while the sum is 46.

The square root of 66808756 is about 8173.6623370433. The cubic root of 66808756 is about 405.7680006293.

The spelling of 66808756 in words is "sixty-six million, eight hundred eight thousand, seven hundred fifty-six".