66756688 has 30 divisors (see below), whose sum is σ = 137406446. Its totient is φ = 31412736.

The previous prime is 66756673. The next prime is 66756689. The reversal of 66756688 is 88665766.

It can be written as a sum of positive squares in 3 ways, for example, as 26915344 + 39841344 = 5188^2 + 6312^2 .

It is a zygodrome in base 4.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66756689) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2595 + ... + 11842.

Almost surely, 2^66756688 is an apocalyptic number.

66756688 is a gapful number since it is divisible by the number (68) formed by its first and last digit.

It is an amenable number.

66756688 is an abundant number, since it is smaller than the sum of its proper divisors (70649758).

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

66756688 is a wasteful number, since it uses less digits than its factorization.

66756688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14479 (or 14456 counting only the distinct ones).

The product of its digits is 2903040, while the sum is 52.

The square root of 66756688 is about 8170.4766078852. The cubic root of 66756688 is about 405.6625602622.

The spelling of 66756688 in words is "sixty-six million, seven hundred fifty-six thousand, six hundred eighty-eight".